Games that I feel bad for not finishing:

FF2 - I've never been particularly interested in this one, but I still want to finish it. Unfortunately my copy of the game keeps crashing at a certain point, and I haven't enjoyed it enough so far to start over on a different copy/medium

FF8 - I got all the way to the end and gave up because, well, I don't need to start a FF8 hate train here. But I regret having an entry in the series remain unbeaten.

Mega Man X6 & X7 - I am not particularly fond of these entries but as a MMX fan I feel obligated to finish them... some day.

A single Mega Man Classic game - Just one would do.

Games I have stopped playing but didn't decide to write off:
Prinny, Can I really be the hero?
Blue Dragon
Resonance of Fate
Phantom Brave
Penny-Arcade: OtRSPoD

And lets not get into the games that I have yet to start/get into, or even longer the ones I have written off....