I've beaten every one that I played. That's I-IX, Tactics, TA, TA:2, and MQ. I really can't understand why someone wouldn't play all the way through a game unless they don't have time, in which case I don't understand why they bought it to begin with. The list of RPGs I hated so much I couldn't finish them are very few, and in the case of FF I'll still play through just because it's a FF game (looking at you, II).