Sooooo.....I picked up a new 360 Elite because my old first gen 360 died of RRoD. I didn't wait because the store near me had the Fable 2/Halo 3 bundle and it had an HDMI cable, which the new $300 elites don't, so it seemed like a bargain. I have NEVER played Halo 3 before (not a Halo fanboy really, for reasons I will explain soon) so I figured I would install the PC versions of Halo and Halo 2 that I have lying around and replay them before playing 3, since I'm a bit of a completionist when it comes to storyline.
So, I ask you this. Why in the hell is Halo so popular when it is so annoying? I just finished Halo: Combat Evolved an hour ago. Yes, I have beaten it before, but that was back in 2005 when it was released for PC, and even then, I had already played it in 2002 on Xbox and beaten it then. Why do I find it so annoying? THE FLOOD. Waves upon waves of enemies that will swarm you, unless you pass an invisible marker that stops their inifinite spawning cycle. Being that they are the most annoying enemies (especially the exploding ones) I figured they would be removed from Halo 2...
They aren't. I haven't gotten the chance to replay Halo 2 (i stopped after the Brutes started appearing en masse so I never finished it) but I know they are there. And I know from various other websites that the flood return in Halo 3 (Oh JOY).
So, someone please explain to me why this is so epic of a game series when I find it incredibly frustrating and sometimes boring. And don't say the multiplayer is awesome, I don't play games like Halo for multiplayer, I play games like Halo for single player story and experience, and most Halo people I've seen online are complete pricks.

i've played the first one, it was kinda meh. nothing special in comparison to the hundreds of other shooters that appeared on PCs. But I think that's the point, appeared on PCs. Console players are just lacking in good FPS (not as much anymore, used to). It's like a Japanese person coming to the US and trying to eat sushi. the US people think its amazing since they've never had anything better, the Japanese people think its kind of run of the mill in comparison to what they eat

Except that IS why the game's so popular - the multiplayer's popular among the pricks and idiots, and we all know the idiots are much more vocal and visible than the decent people.
And then of course there's the few decent people who stubbornly try to stand their ground against the retards, just like almost everywhere else.

The biggest problem is you're comparing Halo to PC FPS's.
Even the Halo Fanboys that played computer games admit that Halo had nothing on the mechanics of PC games.
Now with that in mind, Halo is one of the best console FPS's I've played.
The flood suck, until you notice something... they look a LOT more numerous than they really are. The little ones explode with almost zero damage (playing normal I just let me blow up on me and don't waste the ammo on them), but when they blow up they take all the little ones around them. So you have a cluster of 10 of these little flood things running at one, and you shoot one and they all die. It's all smoke an mirrors made to make you feel like you're being overwhelmed. Honestly from a design stand point it worked. Also I've never found a place yet with "unlimited" flood, there was always a limit if you wanted to hunker down and turtle.
Now from a multi-player stand point, it's a decent game, but doesn't hold a candle to any PC FPS's, but I can see why people would like it. Fluid controls for the most part, variety of weapons, and from what I've been told good MP map design.
Storyline... this honestly has to be one of the best FPS story lines I've come across. It's worth it to see it all play out. There is a bit of a gap between 2 and 3 that doesn't get covered very well in the games themselves, but they tried to clear up with a comic. Simple version... Humans find out a prophet is on the forerunner ship and fire a MAC gun at the room the prophet was in (by tracking a human that was taken prisoner) forcing S-117 to jump off the ship... he lands on Earth and then Halo3 starts up.
Also while you're playing Halo 3 try to find all the marathon terminals, that little background story is kinda neat, about the first flood invasion.
Now with all of that said, if you want to play a FPS, go for the PC, but if you're stuck on a console, Halo isn't that bad.

I played the first few missions at a friend's house, and it was pretty weak.
Even the multiplayer sucked. How do you screw that up?

I agree completely with everything Sielle just said. Are PC shooters better? Yes. However, the Halo series are a very good series for the console. I enjoyed them.

Towards the end of the game, in the pillar of autumn heading towards the reactor, there is a tiny doorway that an infinite number of flood will come from, all exploders and converts.

Ahh, must have missed the fact that they never stopped spawning there... by that time I had gotten in the habit of just running past most of the flood and not bothering to kill them unless they were blocking my path. (Shotgun + run&gun)

Well said. +1 Kudos.

Halo is a pretty solid FPS, until you crank up the difficulty to Legendary and then it becomes a really very good game. I didn't mind the Flood to be honest, I thought they were reasonably well implemented in the first game apart from maybe the Library level. The addition of the Flood forced you to adapt your approach to the situation especially when enountered with pitched battles between them and the Covenant. It was well balanced and I really quite enjoyed the game.
I was very disappointed with Halo 2 though , it felt rushed, the story was often incoherent in its presentation, the level design wasn't as tight as the first game and the combat wasn't nearly as satisfying, especially since they ruined the pistol.
Halo 3 was a little better, but it certainly doesn't pull up any trees. I'm a singleplayer only gamer so I cannot really comment on multiplayer.
As a whole the series is pretty run of the mill to be honest, the first one was pretty good, but the sequels are fairly average.

Just chiming in to say I mostly agree with what Sielle said. In comparison to PC FPS games, Halo wasn't all that terrific. I imagine one of the reasons the game was so well received was because of the dearth of titles for that particular genre. With good reason, too, since it -still- sucks trying to use a controller to play an FPS game as opposed to a keyboard/mouse combo.
Regardless of that, though, I played the original Halo when they ported it to PC. I don't have Vista on my rig, so I never played Halo 2, but I can say this: the mechanics of the game were nothing special. They weren't bad, but they certainly weren't particularly great, either. What stood out to me, though, and what I liked about the game was the storyline. Was it particularly clever or revolutionary? Well, no... the whole super-soldier angle isn't all that new. But it was still done in a way that made me want to find out what happened next. I found myself invested in the fates of the characters, and if a story can do that to you, then it's done its job, regardless of any other factors.
That being said, fanboys are just that... fanboys. They'll find something to screech about no matter what, and I don't think the franchise necessarily lives up to that kind of hype, but at the same time, it's not substandard, either, which is what some people seem to assume. There seems to be this belief that if it's so beloved by morons, then -clearly- there must be nothing of worth within the title. And I simply don't find that to be the case.

I played Halo and Halo 2 on the Xbox and thought they were a lot of fun (haven't tried 3). I really liked the shield + armor health system and how weapons tended to be better at taking out one or the other. Melee attacks and grenades were elevated to core game mechanics. It featured the first fps vehicles that felt good to me [1]. Halo is one of the few fps that has friendly monsters (ie marines) that don't annoy me [2]. The enemies were adorable like Pokemon and brought me great joy when fragging them. Oh, and sticky grenades. :o)
I thought the flood were kind of boring and easy in Halo (they're much more dangerous and exciting in Halo 2). A whole wave of the little eggy ones can be taken out with a clip or two from the assault rifle. Infinite respawns can trip me up too, but fortunately Halo only has 2-3 sections like that. I didn't find them particularly difficult, but they did disappoint the obsessive-compulsive mass-murderer in me. ;)
I found Halo 2 Brutes fun once I learned they take damage differently then the Elite. They have a huge amount of health but no shields. Head shots are insta-kill in Halo land.
That said, Halo is not the Jesus FPS. I find the PC port unplayable because the player is too slow to control with a mouse (almost as bad as Unreal 2). It is in no way mod friendly. I hate being limited to two weapons. The sequel is probably responsible for the regenerating health fad that afflicts so many games these days. The Library level. And I generally loathe the Master Chief. ... It's still better than Half-Life2 though. ;)
*ducks
I think Halo is an over-hyped but solid console fps that probably deserves better than the scorn it frequently receives on PC gaming boards.
[1] I loved running over people in Sin but the handling was just awful. Half-Life rail cars were a joke. Malice had a fun hoverboard and parachute but I don't think they count (the mini-sub physics didn't seem any different than the player's). Never played Tribes.
[2] Probably because the game is happy to let you kill them, and they have good loot. JUST DON"T LET THEM DRIVE!!! ;-)

Why is Call Of Duty so popular when it it's enemy respawn is absolutely IDENTICAL to the description you just posted?
As for the Halo series, I have to agree that seen from an objective standpoint its nothing special. As far as FPS' go I'd call it a 70-80% title. As far as FPS' on a CONSOLE goes, I'd call it a 90-95% because its one of the leaders in the genre on the specific platform and it was the first ever console FPS that was done RIGHT (yes that includes Goldeneye on the N64). The mechanics of the game are solid, the controls well designed and fairly responsive and as far as a console shooter goes, it's not going to get better without a mouse.
On a different note it was also the first FPS I ever played where I didn't get the impression that my character was towing a trailer with all his weaponry behind him. Limiting you to 2 guns actually made you think about what sort of tool you wanted to do the job, since the covenant were fairly resistant to earth weapons it made sense to dump one in favour of a plasma rifle but then the flood were fairly resistant to plasma so you had to balance.
The story was moderatey generic yet interesting enough to hold my attention, the one man army / only hope for humanity thing was annoying but the whole misdirect about the Halo installations was an interesting thing I didn't anticipate.
Personally I think it was better than both Halflife 2's gimmicky bullshit ("Here gordon, have your signature crowbar you remember using in the first game, I'm sure you two have a lot of catching up to do" & "Here's the only gun you'll ever use hereafter, physics, LOL!") and Goldeneye's valiant attempt to do something different but which ended in failure because of the limitations of the system
Is it a good game? Yes
Is it a great game? No

Halo is underrated and overrated simultaneously!