My advice is...it's a game so play whatever you enjoy. If your goal is to have fun, there is no better way than to play what you like.
R/S is certainly a viable toon, though now it is considered a "support" class. Don't see too many R/K's around anymore, the top rogue is the R/M, you'll see a lot of those. Tanks are usually in demand, top tank is the K/W. Priests, in general, are treated like second class citizens, which is too bad imho.
If you are interested in trying out one of the "top" or "popular" classes there are other threads on this subject.