360 has a really good lineup but I don't think it matches PS3's.
From an average gamer's perspective 360 has (that is console exclusive):
- Mass Effect 2
- Halo Reach
- Splinter Cell Conviction
- Fable 3
- Alan Wake (to some extent, not very well known in real world)
- Crackdown 2
That's about all the games that are mainstream. So very impressive lineup. But PS3 has:
- God of War 3
- Heavy Rain (It's iffy if you can call it mainstream or not)
- MAG
- White Knight Chronicles (arguably mainstream)
- Gran Turismo 5
- Final Fantasy vs 13
- The Last Guardian
- ModNation Racers
- Agent
And games that aren't confirmed but could be 2010 are Resistance 3, Killzone 3 and Twisted Metal PS3.
Really it comes down to taste. I really like the look of GT5 and ModNation Racers; all that interests me on 360 is Splinter Cell and Crackdown 2 to some degree.