Actually, I didn't think highly of playing tennis on my XBox either. I picked up TopSpin as a rental, just based on many recommendations I'd read. No one was more surprised than I at how fun it is. :) Although I think Outlaw Tennis will be more fun. In a perverted way of course. ;)
TopSpin is a great tennis game! I'd put that as my number 7, right after GTA. :) I just read up on the upcoming OUTLAW TENNIS. If it's as fun as TopSpin with the Outlaw humour, I'm in there. :)