Final Fantasy 3 (DS):
Freelancer: 1/10. Pointless. The one point is for the 5% of the game you're required to use them.
Warrior: 8/10. Best physical Job in the game, and around a long time. Why not higher? Because other physical jobs aren't so far behind that replacing them with something else is do-able.
Thief: 5/10. It's pretty bad in the first half of the game, but gets actually fairly good in the second half. Was considering higher except that you kind of want to use one in that first half, at least part way, for it to be good in that second half. Steal in theory is neat for Scholar for hording Bomb Arms, I guess, but don't think I can give too much credit for that.
Monk: 6/10. I can see giving this higher if you got a lot of JLevels on it such it's Unarmed Attack actually does good damage; for me, that was never the case, so what we had was a decent but not-spectacular physical fighter who gets outclassed. Mostly good first half to be alongside Warrior so you can save cash, equips, etc.
Red Mage: 8/10. Weird Job where everything sort of falls into place. The JLevels they get let their Healing magic be sufficient the entire game, have the rare combination of Mage-level Magic Defense and offense that comes close to Physical Fighters (Physicals > Magic in this game), and in worst case scenario, can double up on shields, go in back row, and work as tank healers. Resources are a little low at first, but honestly, the pay off is well worth it.
Black Mage: 5/10. Pretty much the opposite of the Thief. IT's got a strong first half, having Bows for damage, and magic being actually decent, but really weak second half. Thief's 2nd Half > Black Mage's first half, though, offset by Black Mage being good out of the gate.
White Mage: 6/10. Battery Healer, the fact that Red Mage is actually good this game at a lot of what White Mage has does hurt it's appeal value though. Main reason to use it is for the MP.
Knight: 3/10. Tank PC that isn't as tanky as you'd think because Knight Armor gets outclassed and doesn't upgrade until Diamond Stuff shows up, Cover is unreliable since enemies often hit past the near dead status or use Magic, and on top of that, has a legitimate Mid-Game Weapon Lag, where Blood Sword is it's best until Defenders, and Defenders are it's best until the Labyrinth (Stoneblade.) All other jobs get SOMETHING to compensate (Warrior's Axes, Red Mage's utility, Dark Knight's Katanas, etc.), Knight does not, and it already has some offensive issues. Ragnarok + Excalibur does give it legitimate offense to be fair, but that's final dungeon only.
Scholar: 5/10. Weird Job. If you use one the entire game, they're actually worth something, but if you ever stop using one, they won't be. The big thing they have going for them is your best source of Magic Damage by far due to Double Damage Spell Items, which are great for nuking bosses, specifically CoD's Tentacles. Their damage is better than you'd expect, and they have Mage Magic Defense, but if you're going that route, you'd probably be questioning "Why not just use Red Mage?"
Ranger: 4/10. Turns into something decent after a point, but generally not worth it.
Geomancer: 4/10. I never saw what was amazing about them; they are good at first but really don't last. The random chance of Shadow Flare is a gimmick, but again, unreliable.
Dragoon: 6.5/10. Solid Physical Job with an OP Weapon available early, and Blood Lance gimmick. Loses half a point since it really needs Gungnir to be worth something, which is a permanently miss-able item.
Viking: 6/10. What Knights wish they were. Provoke is way more reliable than Cover, their unique defensive gear is way better, and they've got better weapons throughout the game offsetting their worse hits (Knight is the only job that doesn't just destroy them on hits.)
Dark Knight: 6/10. Soul Eater is a rare case of good MT damage, and they have no problems with good weapons. Flaw? Shit armor selection for quite a while making them a little too Glass Cannon for my likings.
Evoker: 4/10. Nerfed so bad from their FF3o self it's not even funny. Ok, Ifrit's Healing is great, and Titan is ok reliable damage, but Shiva and Ramuh have awfully unreliable status, Chocobo is an unreliable Run Away, and the 3 Elemental Summons damage just isn't as good as you'd like.
Bard: 2/10. People argue they have these cool uses but the numbers suggest otherwise. sorry if I can't respect 10% Free MT Healing when Red Mage's single MT Cura heals way more.
Black Belt: 1/10. AHAHAHAAHHAHAAH no. Upgrade of a Monk...in theory. In practice, Monk has all those JLevels making it a way better job...and this Job is JLevel intensive to boot.
Magus: 4/10. Don't really respect status this late seeing as your offense in Eureka is high enough to cut things down fast, and enemies in the Side Quest areas are even worse.
Devout: 7/10. Yeah, you want one of these for the final dungeon...
Sage: 7/10. Or one of these, if not both.
Ninja: 6/10. Decent physical job, though not spectacular. I guess Throw lets it take a defensive build (wanna say it can use Genji Shield) for bosses, which is a gimmick.
Summoner: 4/10. Good for Eureka and Side Quest areas, where you fight groups, kind of meh elsewhere. It's only use in the final dungeon is blowing up one of the CoD's Tentacles, and really, Sage does that fine (or Scholar if you're using one) while also bringing another Healer in the mix. The fact that it's late and the fact that 3 of the 4 late game dungeons are heavily "Single Large Enemies" formations instead of groups really kills this job's use. Bahamut's good damage, but decent physical jobs compete.
Onion Knight: 1/10. Gimmick Job gotten via Mognet shenanigans only *flush*