Definitely launch Skyrim. It was my first time with the Elder Scrolls franchise (or any Bethesda game for that matter) and I knew that they were infamous for being buggy... but I had no idea how bug ridden the game actually was.

My least favorite bug was in the "Break of Dawn" Quest in where you speak with Meredia after purging the temple. I had to restart about 10 times because instead of bringing me back down to the land, the game just dropped me to my death. Quite infuriating. @_@

More recently, a game with a few bugs was Batman: Arkham Origins. Luckily I didn't run into any game breaking or save corrupting ones, but here's a picture of batman standing on an invisible van.

Skyrim PS3, worst part is that betheseda did barely anything to fix it, at least for the ps3 version.

I haven't played Skyrim...
The Mass Effect port on PS3 that was part of the trilogy was pretty buggy...
I'm not sure it's the buggiest game I've ever played, but it was the first game to come to mind...

Playstation All Stars is the most bug ridden game I've played and it's not open world.  It runs at a good framerate, but if you play the game, especially online, guaranteed the game will screw up on you.  From freezing in the middle of the match in less than 30 minutes, to graphics textures  when moving past graphics textures where the object was before still on the screen so 1000 different images of a moving object until the game freezes, Zeus's level three instead of him looking towards the screen, it shows his back and he's turned around the opposite direction, etc.  Those aren't even the half of it.  I've seen so many bugs and glitches on Playstation All Stars that no other game can compare.

Two people mentioned Dead Island XCom. Dead Island lag and screen tearing on the PS3 makes Skyrim look as if it runs like a dream. XCom Enemy Unknown was yet another extremely laggy game on the PS3 when starting missions or returning to base, but it was far worse on Enemy Within. The framerate seemed to clear after 5-20 seconds, so the game should have just had more loading time to mask most of the issues.

Mobile Suit Gundam Seed Never Ending Tomorrow is yet another. I'm not a Seed fan, hate the series, but the game looked like it was going to be play like Mobile Suit Gundam Encounters in Space, the best Gundam game imo. More like Mobile Suit Gundam Seed Never Ending Lag.

I've played Skyrim on PS3, but it was the legendary edition with all the patches included. Lag spikes and slowdown have been minor, and I've only came across one bug, a mammoth being pulled straight up into the air then dropping straight down and rolling around after it hit the ground.

True Crime: Streets of NY. There is no way that game went through beta testing. I heard it's almost impossible to finish the Xbox version.

The runner up is AssCreed 3, which is the game that's getting most of my attention now. I am so glad I didn't pay full price for it.

Edit: Scratch that, the runner up is Tench: Shadow Assassins on Wii. Rolling away from guards would transport you halfway across the level sometimes, the collision detection breaks the immersion of being a ninja all too often, and sometimes I'd get a huge laugh out of dead enemies thrusting their pelvises into the gorund with all their might.

Skyrim. Absolutely criminal, which is why I will never support them with a day one purchase ever again.

Fallout New Vegas

I finished all main missions and as much side missions as I could and at the end I still had 6 or 7 left that were just broken.
Never happened to me in any Bethesda developed game.

Gothic 3, Fifa Manager 06 and more recently Batman: Arkham Origins.

Resident Evil 6 omfg!

Thats not true at all. I got the PS3 version and i didnt come across any major bugs. Actually i cant remember any at all. The worst it happened is the game      "crashing" in a neverending loading screen. With auto-saves it didnt become a huge problem though.

I got the legendary edition though.