I only know of swain and wukong, so I can only advise you of those two.
Pros: He has a snare and a slow for crowd control, he has a lifesteal ult that just so happens to be an aoe as well, his damage comes over time, which makes it hard for enemies to gauge just how close swain is to killing them.
Cons: He is -very- difficult to master, and his ult is easily countered. many will tell you that the amount of skill he demands outweighs his playability. His snare is severely delayed -and can be avoided if the player is anywhere inside the circle- while moving (assuming they are uninhibited). He is also item DEPENDANT. His damage is terrible without proper CS.
Pros: He's very versatile, and can range from pure AD to tank, to anywhere between. His ult is a disrupt and deals consistent damage. He has plenty of damage from his base attacks, and all of his skills are icing on top.
Cons: His W is countered (somewhat) by oracle, which is a risk run by all stealth characters. He has no built in sustain, making it hard for him to maintain lane against champions with sustain (Warwick, Shen, Swain, etc) He is difficult to master, though not terribly so because his skills can be used to farm effectively.