A lot of people either have Morrowind or Oblivion or both. And I really don't understand why. Morrowind was even worse than Oblivion and Oblivion was already bad. The game was huge, but there was little to explore and little to do. Every cave, every location is the same with nothing interesting. Some of the cities are big and impressive, but very few people walk around and even fewer you can interact with. Not to mention if you want to enter a building you got a freaking long loading screen every time. And because of that I didn't really want to explore. I am also blaming Bethesda here, because they had to release it on the consoles and then not tweaking it for the PC.
Also the gameplay was very unbalanced and piss easy. I could walk backwards faster than NPC's can run, making it easy to kite everything. But even if that wasn't possible a mage/rogue skill combo destroyed everything without even breaking a sweat.
And then there were the bugs... So many of them. The final straw was the one that broke my savegame.
I know 'favorite' is a subjective thing, but Morrowing, Oblivion, really? Haven't you guys ever played Gothic 2? For the record, Gothic 2 had issues also. It was still better. The only thing that (probably) made Oblivion great were the community mods. But I will not stand for an unfinished game more akin to sandbox game, where the players have to create the rest themselves.
EDIT: Minecraft is the exception here. But that's a whole different story.