Finally a good topic. I've got a number of these
Jean (Breath of Fire 2) - So not only is this a gross stereotype of a frenchman, and much less comedic than perhaps he is intended, he also has abysmal speed, low attack, no good magic skills to speak of and only becomes useful after being fused with the holy shaman - which in turns means neither Nina or Bow can get their fusions, which are a still a better choice.
Marle (Chrono Trigger) - So, maybe "useless" its a bit harsh since there are no useless characters in this game, but I'd say she is... the least useful. She never makes my party past mid game tbh because she is focused on healing and support, yet never learns her own group healing tech that doesnt involve another character. Frog and Robo become more useful as healers and mid/late game and Chrono learns Life. Magus and Frog learn the same lever water techs as she does and she has somewhat of a low attack, hp and speed. So yeah... Sorry Marle.
Mallow (Super Mario RPG) - Similar to Marle, not necesarrily useless, but the instant you get Geno and Peach, Mallow immediately becomes disposable.
Amarant (FFIX) - Boring and useless. I have no idea why is this a character in the game. Beatrix should've taken his slot in the party.
Caith Sith (FFVII) - Ditto
Suikoden series - Lots of them, but I wanna make special mention to beast characters from Suikoden II and V that take up 2 character slots in the party yet never make up for it with their bad stats/abilities.
All the single-type Pokemons that are not "legendaries", "Mythical" or are named Alakazam - No matter their stats, they never make competitive gaming for a good reason: They are just not as good as you think they are.
I think I'll add more later one, I've got very strong opinions on this subject.
