I'm not trying to be an arsehole, accusing you of being a wuss or anything, but did you honestly find Dead Space scary?

Fun scary is different to legitimate scary.
Dead space is around the old Freddie Krueger movies scary but not camp.

Kind of a tie between these, mostly because of their differing genres:

Medieval 2:Total War, even with so many similar factions, I find it addictive to raise an empire. Also political scheming was fun, but then I discovered Crusader Kings....

Fallout: New Vegas, been a while since a game questioned my moral so, and inspired me to roleplay every playthrough(excluding the first).

Minecraft, the building and gathering is just... delightful.

Mount&Blade:Warband, great game, I didn't even want a story with this one and the freedom, just great.

Legend of Grimrock, a nice dungeon crawler, altought modern game, it still had a nostalogic "taste".

Either Skyrim or Gears of War 3.

Minecraft, without a doubt.

It's not my favourite game of this generation. It's certainly not the most technically advanced, or the prettiest.

But it has had a MASSIVE impact on the face of gaming. Nothing like it has existed before, and the sheer scale of it's influence is unbelievable.

I'm still unclear what "this generation" is supposed to mean, regardless of gaming format. Or even what "pinnacle" we're referring to, if not graphics. Most influential to industry? Best story telling mixed with gameplay? Best hack-n-slash casual fun? Best realism? Actual strategy required by the player?

Anyway...it's nowhere near my "fave" game but I'll just say WoW, because for the moment, it has rather defined the mass-market MMO for many years. I'm not saying whether the definition is good or bad (subjective, depends on game, etc), and I think that MMO model is starting to change a bit now, but ... yeah.

Otherwise ... I don't know. I don't think I've played enough games over the past 5-6 years to make a judgement call like that.

I found it slightly disturbing, not that I would actually play it just watched a few clips of action.

Bioshock. I struggle to name another shooter that inspired thought as this one did. From it's story to it's mechanics, it defied the stereotype of FPS's as brainless, instead cementing itself as one of the few intelligent games to come out of this generation.

I struggle to name any game that has inspired thought as this one has throughout this generation of games, and a game of this generation that inspires thought is something of a miracle, and miracles are something I find wondrous.