Suikoden 5 (I to N):
Isabel: 7/10 - Great midgame damage. The better of the Maxmillion Knights.
Isato: 4/10 - He was decent enough during his story sections. Not an archer I'd use much out of forced situations.
Jeane: 8/10 - A mage worth using, Thunder rune in army battles, Charm rune was useful is keeping her alive, plus it was useful having her in the party when I wanted a Runesage.
Jospehine: 4/10 - Horrible, but her Fire rune abilities in army battles were incredibly useful.
Killey: 8.5/10 - Damn Killey's good. Decent physical, long-range mage with lots of speed. Combos w/ other ruins-hunters, who are often forced, gives him an extra point.
Kisara: 4/10 - Serviceable early fighter.
Kyle: 8/10 - All-around solid - strong physical, decent healer, good speed, combos nicely, protects the frail female characters, good in war battles. He was always part of my team if possible.
Lance: 0/10 - Oh god, it's horrible.
LeLei: 5/10 - A preferred earlygame addition. She's a great tank, but she falls out of usefulness early on.
Levi: 7.5/10 - Great mage, not quite as useful as Jeane, and comes a bit later, so he felt redundant. Especially since you have Zerase by that point, too.
Logg: 4/10 - Serviceable earlygame fighter.
Lorelai: 7.5/10 - Often forced, but good enough speed/durability that I didn't mind. Needed more mid-range fighters often, so Lorelai works. Thunder rune was nice, decent combos, decent war character, too.
Lu: 8/10 - Great midgame character. Multi-hit long-range character for the win. Durability sucks, but she's long-range and hardly ever got hit. A fun addition to the team. Character was annoying as fuck, but she was surprisingly useful.
Lun: 5/10 - Good earlygame fighter, only a bit better than her parents.
Lyon: 10/10 - Often forced, but who cares? Lags a bit in the middle, but availability (and usefulness) early make up for it. Better than the Prince in many ways.
Maroon: 2/10 - Dear god, it's horrible.
Mathias: 6.5/10 - Good midgame mage/fighter. The slightly-less-good of the Maximillion Knights.
Meroon: 3/10 - No combos worth using, frail, not good really, though not as bad as the dragonhorses.
Miakis: 10/10 - She's really that good. Does everything well, great combos, good in war battles, too.
Miroon: 3/10 - Not horrible, but still not good.
Moroon: 3/10 - ditto.
Muroon: 3/10 - and one more.
Nakula: One of the few characters that I never got around to actually using.
Nelis: 8/10 - Great mage, decent physical damage, excellent speed.
Nick: 3/10 - Beaver-level.
Nifsara: 6/10 - Not bad, but joins too late and too low-powered to be of much help. It was nice to have a Sialeeds clone, though.
Nikea: 5/10 - Average midgame fighter. Boar Rune just barely makes her average, though.
Norma: 9/10 - Oh wow, she's great. Combos with gamebreaking-Ernst and in one of the pretty girl combos, has Treasure Hunter, useful in war battles, good strength and magic, and speedy to boot. Not the best at anything, but no real drawbacks. Great package of a character.
-Djinn