Hi
First of all, i'm really sorry if my english isn't really good, i'm french canadian and it's not my first language :)
I just need some help, because i don't really have any good top champ and i wanted you guys to help me. I'd like to play a really good tank. Damage isn't my priority. I've thought about Cho'Gath, Nasus, Shen and Wukong, but i really don't know which champ to buy (it can be another than these)
Thank you and sorry if something is missing or is wrong.
If you want something tanky, Nasus is not all that cool unless you are good with last shotting minions to get your q rolling, once you have about 150-200 stacks getting q to build further is really easy.
Cho'gath is great for anti mage work with his silence cone and bounce is just plain annoying.
Wukong is not a tank, not meant to be a tank, he makes a great in and out initiator with his ulti but he is a fighter, not meant to sustain a lot of damage, but meant to do a lot and get out. While its good to build him semi tanky, still not a main tank, more of a tank destroyer with the q.
Garen is an easy to play noob choice that is very tanky and can build pure tank yet still do a lot of damage with his ulti, be prepared for people to call you a noob for playing him however.
Malphite is a great supertank and has a great teamfight initiator.
Volibear is probably my favorite easy to use supertank, his passive can win fights cause people think they got you then boom you are super healing.
Mundo is another awesome supertank his slow knife and packs a lot of damage with w and e, problem with mundo is he gets banned a lot in higher tiers.
I think what you have to ask yourself first is whether or not you want to be straight up in the thick of things while solo laning. A champion like Gnar, Jayce or Cho'Gath can get really tanky and have the range you need to stay away from the other top laner. However, I think they take a little bit longer to really bulk up using items. On the flip side Nasus, Shen, and even someone like Alistar can be really tanky pretty quick, but you'll be right up in the thick of things with melee attacks. I like seeing Shen top because he's got some pretty great late game utility and I think he's pretty easy to get the hang of. It'd probably be a good idea to get one character and then test others as they come out on rotation to see if you like their moveset and how they played. That's usually how I see if I want a new support or not. And heck, I've even run a Lulu tank so almost anything is possible with the right items :)
top always works. you can build him tanky and his abilities give you damage anyways. These guys work well too :) 
Wow thank you guys for the really quick answers, I expected that the first answer would be tomorrow :p
Iaeko13: I want melee attacks :p Because sometimes i'm getting tired of playing squishy long range champs.
Maltech: I don't like Garen and i heard that Malph had an horrible laning phase. Is that true ? But Mundo and Volibear are great ideas, i'll try them :D
Last question:
I'm hesitating between Singed and Volibear ? Which one do you recommend me ?
Jarvan is pretty awesome too. He's a little more damage oriented though. For some reason, though, he tends to get tanky later on.
