Big budget AAA to tiny obscure indie -- what is your favorite game series?

While I certainly have games that I enjoy more outside of this series -- and in fact many of my favorite games aren't in this series -- I have to say IMHO the breadth and scale of this series of games is unmatched...

Assassin's Creed

From getting me to read about the real crusades and Renaissance to wanting to visit New England and the Bahamas, the AC series has been extremely influential in prompting my own geographical exploration and historical research. It has also gotten me to think more deeply about control, anarchy, and society -- a philosophical discussion I have not found in another series. Again, while I have certainly enjoyed games more outside of AC (except for Black Flag which I thought was absolutely great and in my top 5), I can't find another series that has held my intellectual curiosity, interest in history, and love of 3rd person games in such an engaging way.

Quest for Glory. Bringing a character from the very first to the last game in the series, along with the storylines is what I enjoyed most. With the exception of the last game, all of them had the same mechanics, with combat being what changed the most (though not much). NPCs you run into are well written, and being that your past exploits are mentioned (or you run into characters from prior games), it adds to the feeling of having gone through an epic journey. Some of the humor can be bad at times, but it made me chuckle more often than not.

Honestly I try avoid playing it much in hopes that I forget portions of it, so it would be new to me. That generally ends up not being the case though since I've replayed them so many times, so I go far too long not playing the series again.

Edit:
It's also the first game I played where you have multiple methods of completing quests/tasks based on what skills your character had. That was one of the reasons for the replayability.

the Witcher series by far. Just started playing Divinity : Original Sin, so watch this space ...........

Definitely Warcraft (1-3), from the the honorable Blizzard of old.

Perhaps tied with civilization for first place.

Honorable mentions for Commandos(1-2) and Tomb Raider

edit: can't forget Commander Keen!

Hmmm i know of too many solo games that aren't series to really say i have a favorite.

I guess... Megaman... 2-7, and Megaman X 1-3

Yes that was very unexpected though incredibly welcoming news. Now if only someone will one day go to the trouble of recreating all the C1 and BtCoD levels in Commandos 2's engine, complete with indoor levels, then I can die happy. Commandos 3? Never heard of it :)

There was a time when I would've said Final Fantasy, but then IX and X had to go and... exist and that put the lights out on that one.

So, I dunno... nothing, I guess. It's hard to put faith in a whole series and expect it to remain consistently good.

Actually, wait. I take that back. Myst, just a little bit.

For me it's the Gothic series.

Some of my favorites, though some might be more historical than anything else:

* SaGa: I love how the series takes a different approach to the RPG genre. In particular, the series is willing to experiment with the basic growth system in ways that very few games do. It's especially interesting to look at the games that have different races that, unlike the races in typical fantasy RPGs, have fundamentally different growth systems. (Random fact: Many associate the SaGa series with the mechanic where actions determine stat or skill growth, but in the original SaGa that is not the case; Esper (Mutant) growth is pure RNG, with the RNG being a rather poor one that is not affected at all by actions being performed during combat.) I wish some indie RPGs would take this sort of approach instead of using the overused level/experience system.

* Dragon Quest: I especially like 3 (remakes), 6 (original, since the remake took away one of my favorite aspect of the game and actually made game balance worse), and I sometimes like to replay 1 (original, as the remakes I feel took away a major aspect of the game be drastically increasing XP and GP awards). Interestingly, two fan favorites, 5 and 8, are actually my least favorites in the series. (I note that, from a feminist perspective, DQ5 is significantly worse than DQ4.)

* Final Fantasy, or more specifically the classic FF games (FF1 through FF5): This was a good series until the series direction started to change with FF6 (though FF6 at least has the non-linear second world that saves it, unlike FF7 which lacks such a thing). You have the party customization of FF1 as well as the job systems of FF3 and FF5 (note that I consider FF3 the worst of the bunch due to stale enemy design). FF4 has grown a little stale over the years, however. FF2 feels more like an early SaGa game, though unlike SaGa 1, your actions *do* affect stat growth; too bad that game suffers from major pacing and balance problems.

* Also, I enjoy some of the early WRPG series, like Ultima (through 6; didn't like 7), Wizardry (though there are some things I don't like about the Dark Savant trilogy, particularly some of the hidden mechanics in Wizardry 6/7, and I always use save states when playing 1-3 and 5), Might and Magic (2-5, as I haven't played the others), and Bard's Tale (though 1 and 2 have difficulty pacing issues with the entire midgame making the party essentially invincible, except for breath attacks in at least the DOS version of BT1 (which are unfair to the player)).

The one I've enjoyed the most is probably Monkey Island.

The Secret of Monkey Island is a masterpiece in every sense, and a serious contender for best game ever.

MI2, while not as charming continued and expanded a lot of the awesomeness, including one of the most brilliantly designed chapters in the history of point-and-click adventures (Four Pieces of Map).

When I finally got to play Curse of Monkey Island last summer (a game that both real life and a foolish resistance to change have made me avoid), I was glad to find an excellent adventure game and a love letter to what made the saga magical (they even brought insult swordfighting back!).

I've still got Escape left to play, and I hope Tales of Monkey Island, eventually comes back to the store. And a guy can dream with more installments, and even the return of Ron Gilbert...

Honorary mention goes to Age of Empires, the series that ruled during my teenage years. I played countless hours of AoE, AoK and AoM. AoE3 was passable, but I never even bothered with AoEO. Still waiting for news on the announced AoE4...

Hitman series hands down, though my fav game is probably HoMM3.

DROD.

Game series is hard to say. They go up and down. Can I say forgotten realms as a series?
Assassins creed had some moments, however always ruined by the modern day part, and the need to put collectibles everywhere.
For history the age of empires series has to be there.
GTA hit the high notes on 3 and vice city, but Sleeping Dogs (not a part of that series) really pinnacled that genre.
Ultima 7 for me was the pinnacle of that series, never have I created so many maps, notes etc. Outside the early spectrum days.
Mount and blade (if that’s acceptable as series), has to be tied with elder scrolls in terms of modding.
Far cry 1, 3 and primal, great shooters, though also Medal of Honor (war chest era)/call of duty <= 3.
Mario, mortal kombat, street fighter, plus x numbers of others from older console times.
Resident evil1-4.
The list goes on.

Age of empires. Best RTS games on the planet.