I had the same feeling when reading books that take place into contructed complex huge new worlds. The lord of the rings though feels familiar, probably because it is inspired by european myths.

I've been a big fan of Philip Dick as well.
Also enjoyed Robert Silverberg, Frederick Pohl, Ray Bradbery and all the ones from the golden age.

I havent been reading much sci-fi the last few years but often think of checking out the non-american sci-fi scene. A few stuff i read from chinese, indian and russian sci-fi had a refreahing new way of writing.