You don't seem to have any sources listed, like a BD player.
As for your speakers and receiver and amplifier, if you are happy with them, then enjoy them. There is no need to always be "upgrading". That is a sickness that many people have, and you should try to avoid becoming ill. And from looking at your list of gear, you would probably need to spend quite a bit to get a substantial improvement. Experimenting with placement and crossover points might get you better sound, and it also might not. But that is free, and just takes time, if you have it and wish to spend it that way.
I recommend that you spend your time enjoying your system, instead of spending it thinking about unnecessary upgrades. And if you really want the "best", you will need to save up several thousand dollars to do that, and in the meantime, you should just enjoy what you have. Really, it sounds like you have a very respectable system, and you should just be enjoying it.