Spore has to be on my list of best computer games ever. The whole thing is based on creating your unique creature as a cell, swimming around eating bacteria and evolving it over time until it controls a galactic civilization packed with your creations. It is an original idea and I think they pulled it off really well.
My favorite part about the game is the controls you use to change your creature as it evolves, you can do just about anything you want which will makes all the creatures bizzare and interesting. You get to choose if you want your creature to be cute and cuddly or just plain ugly. I find that part of what makes the game so satisfying is just watching how your creature in gameplay. It has absoloutly beautiful animation and and great sound this really makes your creature come to life.
Alot of people seem to disslike spore because of the DRM system it has in it which was aimed to stop piracy and means you can only install it three times before you have to ask ea games for a new code. I think this is only a minor inconvinience and that people shoud stop worrying and just play the game because it is GREAT. Trust me.