There are two games that I started but could never bring myself to finish: Final Fantasy II (which just plain sucked) and Final Fantasy V (which I was enjoying but then there was this tower or something, and I just couldn't make myself go on).
also, Final Fantasy III. Got to the END boss, was doing fine until then. Only got close to beating him a couple of times, every other time wiped out my party within a few minutes. What killed me was the first few bosses in the final boss parade weren't that hard. Traded it in and Youtubed the ending.
I felt that way with every boss in FFIII... every one of them would dominate until one (or more) of my party members died and then it was suddenly easy. Of course, this was made more annoying as there wasn't a save before most bosses. After a while, I said
it, and just use a cheat code on the R4.