The Blaupunkt listed above is great...Two auxiliary inputs, 108 band self-calibrating equalizer, crossovers, sub control, changeable display colors, ambient noise volume leveling, DUAL digital FM tuners, and probably the best MP3 and Ipod control I have seen, next to the Alpine glide touch (although the glide touch tends to have problems)... The clarion 955 855 and 9255 are also great...Auxiliary inputs, 24-bit D/A converters good FM tuner, classy styling,etc ...

And pretty much everything else is black that is worthwhile putting in your dash...

Actually the JVC KDSH-X900 KD-SHX750 KD-LHX550 are all half decent decks as well... Pioneer Premier DEH-P770MP DEH-P8MP
Alpine, well to get 4 Volt pre-outs you have to spend a little more than the competition...
Eclipse decks sound really full as well, but the build quality (more specifically the volume and track *****) seem to have erratic problems once in a while...

These are just my personal recommendations... That is not to say there are no other decent decks out there, just these sound good, are reliable, and are more of an investment than a quick fix for the ill-sounding factory unit... That is if you have them hooked up to through their RCA outputs...

If your stereo shop is willing to show you what the difference is between hooking them up with the speaker outputs vs the RCA outputs, take them up on the offer and you will notice that the hiss on quiet passages is almost gone, the bass is deeper and tighter (not to mention sub level control), the vocals sound more alive than recorded, and the treble will bring your factory tweeters to life...The main advantage why I like the blaupunkt so much is the EQ and other sound adjustment features, MP3/iPod control, Superior FM tuner (almost CD quality sound), the warranty (better dealer support usually), steering wheel remote, and "IT'S GERMAN" (well it's designed there, but not built there)...

Hope that helps a little...