Need Suggestion from experienced programmers

Hello everyone... I am C# programmer and CS student... I am writing on .net mvc, and have done many websites for instance: Online shopping, Movie Blogging, Students Managment System, Forum for gamers, also was working on nopcommerce(open source) and was developing plugin for it  etc. But i want to develop myself, i feel that i  need to grow, but i don't know what to start? what will give me more experience in programming,what will help me to get on the other level, because i think that what i am doing right now is too easy for me...

 

PLS GIVE ME SUGGESTIONS...