Spore is more "intelligent design" than evolution. Though I suppose what you're describing is too, Kwaad, but in a little different way.

Honestly, there's a lot of ideas out there that intrigue me... Thing is, its easy to come up with a really high concept, and hard to imagine how it would be implemented or if and how it would be enjoyable...

One thing I'm really interested in is player-created content, but I'd like to see something based off creating an experience through the totality of player-contribution, instead of creating a giant garbage heap with no starting point like YouTube... For example, instead of taking the content and ranking it by popularity like in LittleBigPlanet, what if those same levels were presented as an endless and endlessly variable platformer... You play through levels grouped thematically into "worlds" with increasing difficulty, and are ranked by "how far in the game" you go. Get rid of a big centralized community. Massively single player, I suppose.

How about a game where every person gets to simply build on a plot of land... With unlimited resources... Collectively creating a city, which you can then explore. But you're able to save your designs, and move to a new plot... And additionally if someone leaves their plot untouched for awhile, they get kicked out and someone else comes in... So that the city is always full of life, and endlessly variable...

Or it could be goal-oriented. Instead of a big, endless community, which would just fall apart and be unpolicable... Its like you're building the tower of Babel... You're thrown in with others each with plots of land, and you have to work together, building upwards... trying to reach heaven... Each level gets harder, with more people involved, building to a higher heaven, and of course the wrath of god starts destroying your city... Levels start out taking a half-hour, with only 5 or 8 people, and progress to become weeks-long projects with hundreds... To progress individually, there would maybe be more requirements then simply your team making it...

Like I said, easy to come up with high concepts, hard to imagine how they'd ever actually be implemented...

 Grand Space Adventure - Sounds like X4 (not yet announced, however X3 is out, and it does everything but landing on planets)

Sim Earth - You dont have the level of detail I am talking about. It does not follow the evolutionary path of a single creature, and it dont have the level of detail I am speaking of. But more-or-less. Yes a high tech version.

Fable 2 - Quite possibly, but Fable1 did NOT impress me. 

 My idea is to influence evolution. Not the "intelligent design" wich is the best description of SPORE I have heard to date. I want to watch my creature change from being an ameboa, into a simple insect, into a jelly-fish like thing, into a water-bug of some sort, into a insect, into a mammal (or whatever else you end up turning into) And you can influence the evolution by adding small furry animals, or vitiman rich grass. And smite down the weak to make sure they dont breed. Basically not centered around anything. You could follow one branch on the family tree, or follow it all as a whole. The choice would be yours.

Im dreaming about Diablo 3.

X3?? The landing on planets is essential for me - it should be focused on exploring new planets/regions, rather than flying around (so 20% flight, 80 adventure).

Metroid 3 could be pretty close - if they added RPG elements to it :) 

1 (the geeky one) : a cross between God of War, 99 Nights and City of Heroes. In fact, a MMO mainly based around cooperation, where you'll fight in a beat'em all way tons of ennemies, from swarms of small ones to gigantic ones.

 2 : Okami. Ok, it already exists but something like that, with original stunning visual (in terms of design), a vast world and original ways to interact with it... If you can add a great storyline that could be influenced and interesting deep character, I'm in.

 3 : a game that would simply surprise me and pleased me, which is kind of hard (at least for the surprising part) after 26 years of gaming.

Freakin' Starcraft 2. That game needs to come out. Seriously.

A MMO Space  Sim  Without pay to play - run via a bittorrent system

Freelancer control style,

Gameplay completely based on chaos theory. - No scripted anything whatsover so everything evolves with total freedom.

To have zero randomly generated you'd have a 100/1 computer to human ratio, with computers doing all the menial tasks that humans dont like to do (farming).

 Humans dont die (escape pod), but comps die permantly.

 a 1:1 ratio of ambitious AI to human, the AI's that attempt to run the galaxy alongside humans

A large number of randomly generated epic events to essentially have every major SCI-fi storyline happen randomly.  Multiple can be going on at different ends of the galaxy.  (Invasion, sun going nova, multiple race war, etc...)

 Governments that run everything - AI controlled until a human takes over/assasinated it.

 Planets reproduce AI for their race and faction based on current political control.

Massive end game event to reset the game to near zero with a supermassive black hole.

 creat your own factions and rasie AI as your own thugs.  (semi sims style)  

 Technology woud be advanced by the governments before it gets sold at vendors,  Prototypes can be stolen.

 Treasure hunts that span many sectors in varrying levels of peace.

Coperations able to form and die with a corrosponding stock market.

Black holes that cannot be seen (black) that will randomly transport you across the galaxy to a unknown location.

Worm holes for going between sectors that may malfunction and send you into a random spot a sector or 2 off course.

 Worm holes will form based on traffic between sectors, but at unknown locations between them.

All gates, worm holes, etc randomly generated from the initial server startup, so maps become a commodity.

 You team kill, kill someone,  someone is pissed about that guy being dead, could become wanted, bounty on your head ,etc.  Every action has consequences.  All actions drive the game. AI and humans can be anything based on the needs of the currently exsistant factinons + random events.

A few things about my ideal game.