Not sure what champion to play next

At the time of this article I am level 23 with around 115 wins and I have played few select champions and most would say that my favorite champions are all average at best. So far I have really only mained 3 champions. Singed, Garen, and Caitlyn. I don't like the fact that I feel like I have very little options but whenever I buy a new champion, I end up not liking them. I am best at top lane but I also began playing Caitlyn ADC recently. Never really have played mid besides a few games here and there. My question is base off of the champions that I really have thoroughly enjoyed (I know it isn't very many...) could yo maybe suggest some champions that I would be able to play well and is actually a strong pick right now. I am really good with these champions and besides the exception of Caitlyn I would say most people view singed and garen as average champions. That being said, I feel like my game would really elevate if I found a really strong champ to learn right now. Thanks for the feedack!