1. Cloud. Because he is a one-dimensional character who is far outshined by every other character in the game. Also because he is the Final Fantasy fanboy equivalent of Lady GaGa.
2. Noctis. Because he will be useless and a shitty character compared to his comrades. Also because he reminds me of Adam Lambert. See: the various threads that have sprouted around here.
3. Tidus. They're both equally annoying, yah!
4. Edward from Final Fantasy IV. Because he is a useless, spoony bard with no balls and no fighting skills.
5. Kyle Madigan from Parasite Eve II / The Third Birthday. Because he's a douchebag.
Honorable mentions: Vaan, Leblanc, the rest of the cast of XIII minus Sazh and sometimes Fang.
Tidus has been added. I hastily made this list before scooting off to work, so mods, feel free to edit as you see fit.
The majority of the XIII cast sucks. Deal.
Shannon - took out Wakka because he's not as bad as the two losers following him. And Sleep Attack is the best thing ever.