FFI, FFIII, FFV (smurf that game), FFVI, FFXIII Lightning Returns.

FFIII I just couldn't get into. FFV (I know a lot of you hardcore FFV fans will laugh at me for this) just has a ridiculous difficulty spike at the end where, if you hadn't got a super strong combination of jobs, most bosses are impossible. I got to the last boss and couldn't bring myself to grind out the win. FFVI I've gotten through so many times but then got bogged down in training and getting everything for the last area and never did it... And LR - sod games on a time limit.