I'm amazed nobody else mentioned Metal Gear Solid 4 - a once-tight game franchise sags under an overweight, over-indulged creator. Flabby, unedited, rambling script. Cut-scenes with adolescent direction and emotional impact that's reliably wide of the mark. Game balance that feels like you're either cheating it, or being cheated with punishing trial and error. Probably the most colossal waste of talent in the history of video games for those brilliant artists and programmers to have to work under Kojima and his faltering vision. The gaming press fell over themselves to praise this, and I call Emperor's New Clothes. It's a game that thinks of itself always, and never the player.

There are a lot of games I'd like to mention here, so paring it down to three was difficult, but here they are.
3) Diablo 2. I realize that this is an object of affection for a lot of people, but while I loved the first game and spent many, many hours playing it, the sequel left me cold. It was fun for a while, but whereas the original was loaded with atmosphere and gloom, the sequel is one of the most concentrated, boiled-down loot-whoring experiences I've ever seen in a game. Most hack-and-slashers at least pretend that they're not just about collecting powerful random items, but not Diablo 2. The grating skill system and Blizzard's erratic flailing with regards to class balance didn't help, either.
2) Final Fantasy VII - unbelievably overrated. The original Final Fantasy was one of the first RPGs I played, and it was probably the biggest single factor in getting me into roleplaying games in the first place. I was probably seven years old or so when it came out in the US, and I remember trying for weeks to get ahold of a rental copy from the video store - they only had one, and it was always checked out (although why I was so interested in this particular game at the age of seven, having never even played a roleplaying game before, is frankly beyond me). Eventually I managed to snag it, and for whatever reason, I loved it.
It holds up pretty well after 20 years, and I still enjoy going back to it now and then. Shortly after FF1 came the SNES, and a string of mostly-excellent console RPGs from Square (though not all of them were available in the US at the time).
I didn't have a Playstation at the time, so I didn't actually play the game until it came out on PC, but all along I somehow felt that this one was going to be a letdown. When I finally did play it, I was not impressed. It's not a terrible game, but it's not really that good, either.
1) Deus Ex 2. Not that this game was even that bad; I still enjoyed it, despite... well, a lot of things. But the sequel to Deus Ex could have and should have been so much better than this. Even in modern days, with high-res texture packs and much better frame rates and load times, its glaring technical failures and gaudy "you should be playing this on the couch from twenty feet away" interface continue to agonize. Even if you cut away all of that and just get right to the story and gameplay, though... it still just isn't as good.

I agree completely. If it wasn't for my friends (and my ex-gf) I would never have even beaten the game.

I totally forgot that game (which makes sense actually) and my top 3 is now complete. Boring, bugged, ugly.

I agree, but at the same time don't mind any longer. I've put countless hours into Diablo 2 and it has been almost as fun and rewarding with friends as the sleepless nights I spent with the first game. The gameplay is the same in an essence, and some of the changes were for good and some for bad, but I can't deny that I like the game. Diablo 1 just holds a special place in my heart.
About the atmosphere, yes, I agree completely. Diablo 2 lost most of the first game's gloomy atmosphere and replaced an array of demonic creatures and references with other mythical creatures, which gave it a lot of variety but made it lose a huge part of its soul. All the removed pentagrams, burning inverted crosses and impaled people scattered around, not to even mention the storyline parts and enemy designs that allowed Diablo to have a whole new level of atmosphere with a mostly unexplored theme.
I appreciate Diablo 2 for what it is, but it could never truly replace Diablo when it comes to an interesting theme and atmosphere.
I have huge fears for Blizzard to blow up Diablo III even further away from the series' heart. We've all seen the fluffy lion statues, rainbows and WoW-inspired cartoonish art design. That compared with the gameplay changes that draw from mostly World of Warcraft and other uninteresting titles only make me shake my head in shame for Blizzard. Seeing how they traveled to the boundaries of Diablo's atmosphere with Diablo II, if the really continue to this direction, I can't imagine what a mess the game will be.

i guess i have to agree with prakaa - i loved 'old' 2d cnc series (first cnc and tiberian sun over red alerts). i had big expectations for cnc3. and i didn't finished even one campagin :/ (u played pc demo and i have x360 version)
so - i didn't expect antything from ra3 since it was 'bigger funnier more colorful' :(
on the other side on my list is RE Remake for Gamecube - it is way better than i ever excpected from first RE remake. i remeber when i played japanese import. good old times...
few years later i bought GC just for RE Remake :)

Ok I will go out on a limb here and say you missed out big time. Now I am sure there are a great many C&C haters ready to beat me to a bloody pulp for saying this but I really enjoyed C&C3, especially when the Scrin turned up and totally changed the game. You got the feeling the shit had really hit the fan and yet Kane knew something everyone else didn't. Played it, finished it and loved it. And I was playing C&C since my old Pentium 75.
Red Alert 3 I thought was even better. Yes it was bigger, funnier and more colourful but I loved every minute of it. The acting was Flash Gordon brilliantly hammy and the game was an awful lot of fun to play especially multiplayer. Sure its absolute toilet as far as competitive online gaming goes but competitive online gamers can kiss my ass.

since i gave 'warm ignore' to cnc4 - i don't know if i like what i could discover.
but on the other hand - we have holidays (well - i have 4 additional free days :P) and some time - maybe i should give cnc a second chance.
i dont like funny cnc.
but if u love it - i don't have any problem with that ;)

I thought everyone loved Red Alert 2!

I preferred Red Alert. They nerfed the soviet air superiority in the second, and that pissed me off.

Oh yeah, Migs away!

But... Red Alert was ALWAYS silly. Einstein going back in time to kill Hitler? Thats not silly?

Yep, it was. It was always pretty over-the-top, as compared to pretty serious Tiberium universe - that's why I don't get people complaining about C'n'C3 either...

Thats why I loved Red Alert 3 and Uprising. When it comes to Red Alert I want the silly dolloped on with the big scoop.
*spoiler*
Best part of Red Alert 3 was hunting the Premier, and also hunting the nutso American President.

Caesar 4 - After having played all the "Sierra City Builders" of C3's generation, I had high hopes for the next... suffice to say the hopes were squashed like ants under a flat-soled boot.
Immortal Cities: Children of the Nile - This should probably be grouped with the above, since it's basically the Egypt-themed version of the same. Pharaoh was great (and the first game of the series I played), Zeus, Caesar 3, and Emperor equally so. This generation was a major disappointment though, there's a reason there are no more follow-ups to the series.