I'm looking for a nice deal on a used double-din headunit with a built-in LCD display. I really don't need an LCD but it's just going to look much better in the dash of my car (2005 Mazda3). I don't need navigation and I probably won't be playing DVD movies either but I think most of the displays have DVD players built in.

Features that are important include: Sound Quality, Sound Tuneability (built-in EQ), aesthetics, ease-of-use, hopefully under $600.

If you guys have used any double-din units in the past couple of years and have recommendations please let me know.