Advance > A2 > Tactics for me. I feel like these games work best on handheld and I don't give two trouts about the characters or story, I just want to play with tons of job classes and kill things. Laws (which I liked) and cute races are a bonus. FFTA fulfilled all those qualifications the best IMO.
I like A2 quite a bit but some of the mechanics changes aren't up my alley so ultimately I've gotta hand it to the original FFTA.