You are in a place a lot of us find ourselves: a lot of working equipment that is pretty much middle of the road. If you were to sell most of that gear you could take a step up in quality to a higher level. Less gear, but better gear. It's very easy to pick up a $50 receiver and a $50 pair of speakers here and there, and next thing you know, you've got several hundred invested, and all of the gear is pretty much the same. Whereas if you put a few hundred into one really nice pair of speakers, you'll forget about virtually all the ones you had.
Unless, of course, you like things how they are, but I get the impression from the start of this thread that you are looking for ways to upgrade your sound.