Zed is very good in top lane. A lot of room to play with and get more slashes off. If you're really good with Shaco you can play him top and build him AP. He works against a lot of common tops like Riven. A lot of champs can be played top that are unconventional, you just need to be good with them.
"Life is a sexually transmitted disease" -Anonymous
Malphite is a great top laner. Only champs that tend to mess me up very much tend to be Kennen, Fizz, Jarvan, maybe some others. Champs like Singed, Garen, etc tend to just be stalemates since you usually can't kill each other, then people like Jax, Teemo, etc he can just easily overpower. He gets banned a lot though so you won't get to play him in draft much.
I play Lulu support a lot and have never tried her top, but I've heard (and seen from experience) that she is really good top lane though. Definitely got murdered by a Lulu top once.
Is singed still good haven't used him since his latest nerfs
And for lee sin I will give it a go
You're better off playing renekton than lee sin top as they roughly do the same in lane (are ungankable immovable objects with ridiculous early game dueling) but the croc is better at diving the enemy carry and can initiate without relying on a fluke (someone exposing himself enough for you to kick him into your team).
Singed is still pretty good despite the nerf. You're just less likely to all-in successfully now and get fed in lane.
Cho is a decent pick top, like always really. Just don't play him against garen/rene and the other usually easy mode top laners.
Nasus top is so-so, people are starting to ban him but not because of his top but because of his jungle. Wither makes his ganks really strong. On top he's best used against melee autoattacking dpsers with poor early game and no sustain. Like Jax. He's worse against olaf/irelia but nobody plays them top anymore. Various ranged picks can make life hell for him with phage rushing teemo being the biggest menace. Those picks you see more often.
Still waiting for: Half-life 2: episode 3, Wasteland 2.