I still see plenty of people playing Halo 3, Call of Duty 4 and Call of Duty: World at War, as well as Left 4 Dead. People may only be talking about GoW and Fable as of late due to the latest updates on those titles. Gears of War 2 is getting a title update to fix all the glitches that cripple its multiplayer and Fable II just had an expansion DLC release. Plus in our neck of the woods, namely the tF guys, we’ve got a solid group of people still playing NCAA Football ’09. Plus there’s always Rock Band and Guitar Hero, but again, with the exception of H3 and L4D, the other games are found on PS3 as well.
Honestly, I say the systems are fairly equal. It’s just a matter of which one satisfies your needs / wants with the fewest sacrifices.