Nick, I highly recommend CDT Audio speakers. You can spend a little or a whole lot. Even their lowest end series are amazing. I have their 5 1/4" basic coax in my dash and a 10" sub and it sounds great. I'm kinda picky about this stuff, but I doubt I'll upgrade (or at least don't feel the need to). I have been in a car with the eurosports and the owner had to pry me out of the car, simply awesome.

CDT Audio Website