I'm also adding Dishonored to the list. I pre ordered it and played it the very next day for a few hours, then I uninstalled it and haven't touched it since.
There's also Borderlands, Batman Arkham Asylum & City, Far Cry 2 (don't know if people raved about this one), Oblivion and currently going through the same thing with Skyrim... so much to do. I still haven't met Delphine in Riverwood yet
Just been doing side quests and exploring. I still have The Witcher 2 installed... haven't finished that one either, so I'm throwing it on the list too, but I'll get around to it eventually. I'm also adding Assassin's Creed Revelations to the list as well. I never was really interested in it, but I stopped playing it because I kept getting an error whenever I tried to play it. Well, those are all the ones I played on PC. As for PS3? Dark Souls, Saints Row 2 (did people rave about this?), Uncharted 2 & 3, Killzone 2, Resistance 2, God of War III, Red Dead Redemption, and Infamous 2 (will change this soon probably).
Yes, those are all the games I've started and never bothered to finish. Well, most of the ones I can remember anyway