I think that The ShuangRen and The huanying are just knock offs. I think that DaYan should be the cubing talk around here. Sure, they don't have any updating cubes out right now but they are still the best in my opinion.
I use fridrich but, It can be quite repetitive. I think learning new methods and exploring more is what makes you want to cube more. Yeah some of my friends don't like fridrich but it can be very fast.