i never had problems with morrowind, oblivion and skyrim and bought all at release (really, never) and i'm pretty sure the luck will be with me like always playing bethesda games lol
AFAIR the items in the German Oblivion version were only ~50% translated at release*hurrhurr*.
But really Bethesda has improved tons over previous games. Oblivion was really a bug fest and crashed so often during loading screens when you tried to enter a house. Fallout 3 at launch was already far better and in Skyrim you might encounter a bug every 10 hours which is just as rare as in every other game.
Compare that to Obsidian's Fallout New Vegas, where I couldn't finish 5-8 quests due to bugs and had to wait for a patch to solve them.