Final Fantasy Tactics Advance, above all else.

That being said, Shin Megami Tensei Devil Survivor 1 and 2 are awesome. They combine SRPGs with the usual SMT combat - I don’t think I’ve found something similar yet.

You move around like you would in any other SRPG, then you can attack enemies in range to enter normal turn based combat - however, at most, you can only play out 2 full turns before combat ends. Afterwards the next unit moves. Each unit represents a squad of up to three characters you will be batteling with, usually a human and two demons. Depending on your squad, you may have different movement, range and abilities.