Graw 2 or Guitar Hero 2..or another?

Well I definately need a new game. I am stuck and cannot decide between GRAW 2 and Guitar Hero 2. I played the demo for GRAW 2 and enjoyed it but Guitar Hero 2 looks pretty fun. Has anyone played it on PS2 and if so how much do you guys think it will last. I am also open to suggestions for other games, since I only have:

Oblivion

Gears

Rainbow Six Vegas

Splinter Cell: DA

So what are your opinions? 

(If you dont feel like writing please at least vote on the pole I would love some input)

BUMP

Any and all input is great

Both are good games, but personally, after GRAW1, Gears, and Vegas, the last thing I want is another TPS. I own the PS2 version of GH and GH2 and will be picking up the 360 version on the 3rd as well.Slipin