Definitely Yuna. I loved her kindness, the fact that she's a summoner and uses white magic, and her ambition just really move me. I also just love healers in any game, and they always catch my eye the most, so I naturally enjoy Yuna for her ability to heal her allies.
				
			

 Yuna is a close second, but there are times early on in the game where she really annoys the crap outta me.