Except for the newest DLC for Borderlands. That one sucked completely and my friends and I beat it in under 2 hours except for the bugged achievements. Agree with everything else you said though. And I am looking forward to Crysis 2.
My idea of good DLC is Oblivion's third-party mods. But with one caveat: the game shouldn't be so unfinished it needs mods to look any good.