Sims 3 and basically anything EA Games. There was a period of over six months that it was completely unplayable. Why? Patching. They always rush the release (word also has it they've taken to rotating out development teams which creates a plethora of problems by itself right there) and so it is bugged to absolute hell and then they turn around and drag their feet for months (or, more often now, never) getting around to fixing the problems. And then far too often, what they fix results in new problems and the cycle repeats itself. I'll never touch an EA Game title again. I never get what I think I'm paying for. I haven't touched Sims 3 in three years (only really liked building the houses though so not a great loss. Sims 2 is better for that actually).
Unfortunately this is becoming true of Bethesda Games as well. I love Skyrim but I shouldn't have to resort to the Console Command (PC only) to skip broken quests that have been that way since version 1.0 (yup, even patched to 1.9.32.0.8 and even though its claimed they're fixed, they aren't). They announced they've abandoned it and true to their word they did and they've left too many loose ends in the wake of that decision (particularly considering how much it cost). I still have to skip everything (in the main quest no less) involving Esbern or that damned Vaermia's Torpor that completely makes saving impossible (I mean HOW do you overlook that?). So I also regret, to a degree, Skyrim even though it's my favorite second to Oblivion... third to Fallout 3.
So really, it's the lousy or non-existent technical support post release that ruins games for me in one way or another. I suppose it could be worse. I could be a powerless console platform player without even option to "cheat" a fix.
Oh you know what, I just remembered Fallout: New Vegas. That one wouldn't even install. Haven't been bothered enough to try 'tweaking' it too either.
