Sims 3 hands down-whenever my sims have babies they're either black (and I mean literally BLACK, not ethnically black) or I get this flesh coloured line coming out of the baby's head. It's really irritating.
I have to edit my earlier statement... My mother is hopelessly addicted to Cafe World on FaceBook. Because I build so much on sims 3, she recently asked me to design her cafe for her and change out a few dishes... That by far is the glitch-est game I have ever played. And it is so basic... And so screwy...
I played that for a little bit, too. My character/avatar kept turning back into a man, and I'm fairly certain a customer got stuck sitting once. At least I think it was Cafe World. It's hard to keep track of all those dang games...
Cafe World is terrible.
TS3 is filled with glitches (but I am running it on a system that sucks, so....)
I'd have to say Saint's Row The Third. I'll be driving down the street and see numerous vehicles with people standing on top of the car. People get stuck in windows and buildings and you only see their hands or heads. I blow up a rival gangs' car and pieces of the wreckage attach to me, even if I get into another car.
Two Worlds. Was not a good start from Reality Pump. Most disturbing was the dialogue that looked like it was skipping all the time.
The Witcher was from the start also pretty glitched and actually it was half finished. Huge fps drops and sometimes black screens. CdProjekt Red did fix this with patch 1.3 and with the EE the game was more polished.
Sacred 2 had also it's quirks, until ascaron came with patch 2.34, which solved problems like random CTD's. However, with ice & blood new problems were introduced and since ascaron is no more and deep silver doesn't care they weren't solved. A community patch solve the new problems.