Chrono Trigger: is a balanced cast generally
Crono: 5/10. Pretty average. Good speed, okay damage, no variety.
Marle: 6/10. No damage, but great variety. Double techs do bring her up some.
Lucca: 6/10. MVP at endgame for raw offence... fire is great, she generally has the best damage and it's all GT/MT. Protect helps for surviving Grand Stone too I suppose. On the other hand, earlier she is just a bit too slow.
Frog: 4/10. Kinda the inferior healer overall, and damage isn't really any better than Marle's.
Robo: 7/10. Slow early, but this does get fixed as time goes on and everything else about him (damage, healing, variety in general) is just awesome.
Ayla: 8/10. Best physical damage, high speed, some healing (great healing with Frog), high damage combos in general, and stealing... not sure how much credit I should give it, but CT does have the best stealing ever pretty much.
Magus: 6/10. MT melt your face off. Sorta like Lucca, except only around when Lucca is good. But I guess not quite as good since Dark Matter < Flare, so they can get the same score.
Disclaimer: I rate FE on a different scale than most games. This probably makes it a bit easier to get 9 and 10. I may edit some of these if characters are in danger of being overrated in the final standings compared to other games (e.g. Ninian is a 9 to me but so is Cecilia and Ninian probably isn't as good as Cecilia).
Fire Emblem Lords, Dancers and Other Unique Classes:
Roy: 4/10. He's good if you let him cap early, then sucks. But... not very good. Fast Alan/Lance/Lilina supports are his best attribute.
Merlinus(6): 2/10. His function isn't too useful.
Elphin: 7/10. FE bards are always good, these two are worse than most though due to being frail.
Lalum: 7/10.
Fa: 4/10. Exp ranking booster. Probably a 2 if I didn't care about this.
Lyn: 7.5/10. She brings offence. This is cool.
*Nils: 9/10. Dancer + durability + the rings.
Eliwood: 6/10. As befits Eliwood, lives up to neither his hype nor his anti-hype. He's pretty solid but I wanted a bit more speed or durability.
Hector: 7/10. Eliwood trading some speed for quite a bit of Def, which probably comes out ahead. Wolf Beil removes any doubt.
Merlinus(7): DNR, you have no real choice in how he is used.
Athos: 8.5/10. I rate characters based on how good they are when they're around, assuming they're around long enough to have real use. Athos certainly does, Light is a bitch and he makes it much easier.
Eirika: 8/10. Loads of offence (broken weapons help), durability is initially suspect but becomes great, has move on promo. I'd say she's the best lord between FE4 and FE10, but she has to deal with...
Ephraim: 9.5/10. This guy. Dear god. Would be a 10 if not for a somewhat late promotion. Loads of Atk, Spd, Def, and evade. TWO ridiculously broken weapons. Horse on promotion. Yeah.
Tethys: 8/10. Dancer with some cool supports, though not as initially durable as Ninian and no rings.
Myrrh: 3/10. Fa with better stats, but no Exp ranking.
Ike(9): 7/10. His stats are good: durability and speed are very nice, attack is decent... but he competes with the raw broken that is FE9 paladins and fliers and is stuck with the trash that are FE9 swords, so he has no 2 range, a late promotion, can't move after attacking, and only has 7 move. Was one of the LVPs of my Fixed Mode playthrough. That said, still decent enough for this score.
Mist(9): 7/10. Best staff user. Durability could be better, but gets hax offence if you drop Arms Scrolls on her,
Reyson(9): 9.5/10. Reyson + paladin swarm own puny game before it can blink.
Elincia(9): 3.5/10. Lategame filler healer if you desperately need one, but she's not very good.
Micaiah: 6.5/10. Yeah, she needs speed. On the other hand, if she had it she'd probably be broken. Third best unpromoted DB member after Nolan and Jill, provides a devastating offensive punch and then switches over to healer once it's time to no longer fight knights and cavalry.
Rafiel: 6/10. His lack of canto means he loses out badly to Reyson in over half of his available chapters, and generally his personal chapters favour herons less. Still, heron.
Black Knight: DNR I think? No idea how to consider him. Amazing in his three chapters (although worse than Nailah in one and not around for the first 4-5 turns in another) but yeah.
Elincia(10): 9/10. Yay, broken healer with ridiculous offence.
Leanne: 7/10. Again, loses points for competing directly with Reyson.
Ike(10): 9.5/10. I realise I forgot to mention Ragnell in FE9. This is because Ike has it for 6% of his maps so it hardly bears mentioning. In FE10? Try 50%. Broken weapon, broken stats, and Canto units were nerfed so Ike is now looking really, really good. His endgame could be better I guess but whatever, unless you are overrating that (since he's not -bad- there) this shouldn't drop his score much.
Mist(10): 5/10. Uh she's a decent healer in split paths at least.
Reyson(10): 10/10. Even more broken than in 9 now that he has more move and Grass/Stone/Gem options. This says something.
Sanaki: 2.5/10. Kinda bad.
Lehran: DNR, too annoying to get. (and yes, I've done it)