It is actually easier to play with a big screen TV...You'll be able to see much better and have a better perception of where something is gonna land...great for grenades
Halo 3 is my game that I think need a big t.v. so I'd say a big t.v. But, games like Super Mario Ipreffered a small t.v. so for me its the game that seems to make me want a big t.v. or a small t.v.
It really doesn't matter how big or small the t.v. is, just how strong the resolution is. Low = blurry, nasty images, high = detailed and easy to see. Of course with people around it is nice to have a big t.v. so you're not crowding around a small innocent t.v. Ever try 1080P with certain xbox360/PS3 games? It's a strong enhancement to the resolution of the T.V. so it is extra detailed. Images look very smooth and detailed its not even funny.
My T.V. of course is a 60 incher, and it has 2000x2500 resolution. It also supports HD, Progressive Scan, and 1080P. I bought it for $2,490 I got a great deal out of it, I died a happy man = )