It kind of depends for me. I think of all the games, Asbel is my favorite to control; he's got a good amount of speed without being a bit unwieldy, the balance between sheathed/unsheathed artes words for me, and I just have fun maining him. And my AI does way better with the other character in Graces I enjoy playing, so there's that. Asbel's also the one I've really mastered combat with, chaining combos and getting CC bonuses and whatnot. I've sunk more hours into Graces from the sheer enjoyment of just fighting things in the Zhonecage on chaos mode than any other Tales games I've played.

I think I generally tend to stick to the mid-range/balanced, sword wielding protagonists (Yuri, Shing, etc) otherwise, though I main Alvin in Xillia which I find surprisingly fun for being the big slow guy. Ludger's a lot of fun too. I pretty much just sit on the boat of "AS LONG AS I DON'T HAVE TO PLAY CASTERS."