I personally love playing Renekton solo top. If you use the right masteries and runes, you can make his early game sustain very good, enough to survive ganks which would normally kill someone.

I also like playing Riven solo top, she does great amounts of burst damage and her ulti just makes her do more damage and have a ranged attack to finish off running enemies.

ALSO, I like playing as Irelia solo top. Her and Akali. They're both dominative when they have all 3 abilities before their ult.

But they're just my likings. I'd hope they showed some form of insight as to what you may like,

A good top solo champion could also be Talon. His burst combos are just so fun to initiate.

Darius

I've been using Jarvan lately and with the right build, he does a pretty great job at top

Olaf, Darius, Renekton, Yorick, Tryndamere

Yorick is incredibly fun in a 2 v 1 top lane. Harass them, maybe zone once, run away if both come at you, then when you hit 6, draw them out and get a double kill.

I've been playing nautilus solo top for a while recently, and I really like him there. Sure, you don't get to take advantage of ganks like you could if you were jungling nautilus, but because you get more farm you'll be able to get more items to do crazy amounts of damage late game, while staying tanky.

Also, poppy is a lot of fun, but she can be countered pretty easily. She's a very situational pick, cause she either counters the person or gets countered hard. She's only a 450 too!