Tales of Legendia:
Senel: 9/10. Really good Tales main. Hits hard, has great durability and good equip options, and even techs and weapons tailored for specific bosses! Wow!
Will: 6/10. He's...the second best mage? It's either him or Shirley, though I think I lean towards Shirley personally? Healing and defense boosting is nice, and his durability is good, but he gets hosed on the physical, and doesn't get real good are effect until the Blades, so...eh. Still good, and he's serviceable until the end, at worst. Always found him to have the worst AI of the mages, for what it's worth.
Chloe: 7.5/10. Senel with a bit more range on the physical, much less durability, and less elemental variety, and damage...but hey, she's really much better at keeping enemies tied up, with really high combo potential, so...that actually counts for a lot here.
Norma: 9/10. The best mage in the game. MT healing, revival, has all elements, good AoE effects, etc. Worst durability, blah blah is made up for by having Taunt and Rally. Also has one of the better physicals and good equip options. 2nd worst AI of the mages on average, but so much better than Will's it doesn't matter nearly as much.
Moses: 7/10. Uh...best AA of the entire cast. He's also a decent enough long-range nuker, and has the best AoE of any fighter (well, Jay might be comparable, but Moses can do his from long range, so...). That said, it's harder to hit with his skills, but his durability is good, he's awesome AA as I said, and he's not bad overall. Best long-range attacker until Jay joins.
Jay: 9/10. Dagger. It's his best skill, and it's his first. Decent damage early, great damage later, and if you get Extreme...yeah. 4000 damage for a cheap as hell tech that flies the whole screen is...insane. And outside of that, he's good at combos, has solid damage, elemental control (best of the fighters, with techs and weapons - barring Senel, who comes close on weapons), and is good enough on durability (though you never need it).
Grune: 4.5/10. Worst mage, and worst character. Her magic is very, very limited (1 weak ice and weak fire spell, and then all sea and curse), and she has nothing but attack magic. If her damage were supremely awesome here, then she'd be better, but it isn't. She's got an awful physical too (gameworst), and, while better AI than Will and comparable (or better by a bit) than Norma's, the lack of other skills limits the usefulness of that a lot. Has a good unique title, and decent enough armour, but...otherwise not that great.
Shirley: 6/10. She might be better than Will, the more I think about it. Late-join, but that doesn't matter - he starting spells are stronger than most of the higher-level ones. Also has healing, offense and defense boosting to round her out. 4th best physical in the game too, and she gets all but Curse element. Also has the best AI of the mages, which works well with her.
Digital Devil Saga 2: Eh, not a huge amount of comments for these. Mostly similar to DDS1
Serph: 9.5/10.
Argilla: 7/10.
Gale: 7/10.
Cielo: 6.5/10.
Roland: 5/10.
Sera: 8/10.
Seraph: 10/10.
Heat: ...5/10. Really depends heavily on how you build Roland.