if you've got an ipod or plan on getting one alpine will be integrating them into their newer HU's. they'll be releasing a module this summer which lets you not only access all your mp3's from your ipod but gives you full control via the HU as well. this is not the same as simply plugging your ipod into an auxillary input on your headunit. it will let you browse through your files and view the mp3 tags as well. pretty cool stuff. plus it's supposed to charge the ipod at the same time (like when you dock it at home).
just an interesting alternative to consider.
idk if you were looking for a hard drive HU that you can store mp3's on or one that jsut reads mp3's from cd's...
right now i have a kenwood hu, that plays mp3 cds. its worked for me ok so far. i really like it. and it has blue back ground to match my hvac and gauges. its pretty affordable as well around 200-250. last time i checked. or if you want to go nuts just get the music keg from kenwood. i am using that as well, and i love it so far....hope this helped out a bit...
I'm also in this boat. I'm looking for something cheap that plays the MP3s. I've had nothing but good luck with Pioneers over the years (hey that rhymed!), but I'm open to change. I just saw a Pioneer DEH-P5600MP for !57 on eBay, but just because they say it plays MP3s doesn't mean they play them in data format. I want the 10hrs on a disc.