Because of trophies and silly little things (like getting a certain weapon which doesn't give you much but is just for completion sake) I class many games as done when some might consider them not. Trophies mainly because they are added bonus and not a game selling feature.
Resonance of Fate - just keep getting distracted by other games.
Valkyrie Profile 2 - not completed and now sold as didn't enjoy it
Rogue Galaxy - not completed and sold, was okay but not great
Transformers PS2 (non-movie one) just didn't kill the final boss.
A few PS1 games I recently purchased, Omega Boost and Vagrant Story, collection purchase really, so newer games took priority.
.... that's it, most other games I'd class as completed. I'm not going to spend my life trying to find that one single item to make another item in FFXII or whatever, I've seen the videos, it looks like a boring task.