I'll reiterate what someone touched upon. It's well established in a lot of gaming circles that KotoR II was never legitimately "finished." Obsidian was nowhere near where they wanted to be, but Lucasarts ended up forcing their hand and released what was, essentially, an unfinished product. They ended up having the hack the crap out of the last portion. Originally there was a scene where Darth Sion actually tortured and killed Atton, the white haired Jedi who went nuts on you was supposed to be Darth Treia, an entire planet was cut out (Remember the droids that were hunting you? It all came to a head there) and loads of other stuff I'm not even aware of. There ARE people trying to patch it to put in as much of the deleted content as possible, though.
I LIKED the ending to Twilight Princess. Zelda games have always had cliche happy endings where nothing much happens of consequence. I also kinda liked Final Fantasy XII's ending, it was intentionally left open to leave room for the sequel, Revenant Wings.
On the other hand, endings I hated:
While it was rushed and understandable, I do loathe the KotoR II ending.
Outside of Blood Omen, the entire Legacy of Kain series has had utter crap endings, especially the two Soul Reaver games. The first one: you show up, attack Kain and he runs away and you run into the oracle, the end. The second game, the Soul Reaver tried to devour Raziel's soul and Kain pulls it out leaving Raziel sitting there confused, the end. Both were the victims of rushed production, but they were lazy and abrupt endings. Then, after a thrilling and heart-pounding climax, Defiance ends on a blah note. It makes me pine for the days of the original Blood Omen where you beat the final boss and damn and enslave the world.