Can you please recommend a lightweight Linux with GUI?

I decided to install 64 bit Linux and run it directly (rather than as a virtual machine). Once I install Linux I will try I-TASSER once again. Having said that can you please suggest a lightweight distributive that would still have GUI and would run I-TASSER? Ideally it should have classic design. Hence, I would like to avoid Ubuntu if at all possible possible. It feels heavy and unstable; "innovative design" translates into puzzles like "where is 'right click' -> 'Open terminal' command?"

Thanks in advance.
Stepan