There are a lot of games I've loved but not completed. When I was younger I would finish every game I played, but I don't have a lot of patience these days and there are so many good games to play.
Games I enjoyed but never completed:
- Quake 2
- Ikaruga
- Zelda: Wind Waker
- Farcry - although I
loved it. It just got silly toward the end
- Doom 3
- Morrowind - played it for about 100 hours, had a blast, then walked away from it without finishing the main quest
- Oblivion - see Morrowind, but only about 60 hours this time
- Dawn of War: Winter Assault & the new one - had a lot of fun playing them, but lost interest when newer, shinier games came out
also, I'll predict right now that I will never finish Neverwinter Nights 2. It is a lot of fun to play, but the storyline sucks, quite frankly. I've put it down for now, and am pretty sure that I'll pick it back up when I've got better hardware & they have some decent user-created mods for it.