Quality brands in my opinion:
Morel, Hertz, Crescendo, Alpine (older gear, not speakers), Pioneer PRS series, SB Acoustics, Fountek, Vifa, older Nakamichi, Focal, DLS, Audison.. These brand generally represent good quality products, though as said above, the stereo is only as good as the install, leave some of your budget for sound deadening and allow a lot of time to run the wiring properly, build proper enclosures and install everything correctly.
I use a $70 (Carefully chosen) midwoofer in my car, in a 2-way active system and I have only entered 1 SQ competition since installing my front stage, but they faired well against other $1500 front stages in my division.