I've owned it for about 3 years now and there are still lots of big titles that I haven't played yet.
Titles like:
HALO
Bioshock
Minecraft
Mass Effect
Batman Arkham Origins
Mirrorsedge
Left 4 Dead
Dead rising
Skyrim
Red Dead Redemption
Dark Souls
Fallout
Fable
Guitar Hero
Assasin's Creed
Far Cry
Rainbox 6 Vegas
State of Decay
These are all games that I haven't even played once. And a bulk of these games make up the most popular games on Xbox 360.
The types of games I play usually have more replayability. Since I'm an older gamer, very rarely do I have time or patience to sit through long campaigns anymore. I play games like:
GTA V
Madden
Portal
Half Life
Poker
Forza 4
Skate/Skate 2
Call of Duty series
Fight Night
and a bunch of niche arcade games ranging from Limbo to Marvel vs. Capcom 2.
The only types of long campaign games I'll play are games developed by Valve (which is why I plan on buying left 4 dead 2 and possibly the first one as well), but other than that, are any of the games above worth buying considering next gen is already here (granted that I don't plan on buying next gen consoles until they've ironed out all the flaws)?