Here are champions that I find really enjoyable to play, I would definitely recommend giving them a go.
Top: Riven
Jungle: Lee-Sin
Mid: LeBlanc, Twisted Fate, Ziggs, Ezreal, Nidalee
ADC: Sivir, Ezreal
Support: Thresh, Annie
Reasonably good mechanics are required to be successful on the majority of these champions (specifically Ezreal, Nidalee, LeBlanc, Twisted Fate and Lee-Sin). So if you don't feel confident landing regular skill shots and such I wouldn't recommend going straight into them. Otherwise go right ahead, practise makes perfect and these are some of the most rewarding/enjoyable champs in the game in my opinion