To be honest, HUs are VERY difficult to suggest as EVERYONE has a brand or type that they think is the best.
Just like ALL brands, there are the loyal followers who will swear theirs are the best and everything else is sub-par.
My suggestion is to go to your local stereo install shops(plural - so visit a few) and look at ALL the HU's. Play around with them, as what ALL the functions are and how they differ from each model, and from each brand. If you can, come up with a list of options that you want in a stere such as an equalizer, or aux inputs, future intalls, etc.
Me personally, I want to get this: http://www.crutchfield.com/S-GAdNf2...0&id=morephotos&a=&s=0&cc=01&g=300#morephotos
It has ALL the options I'm looking for: Small touch activated screen; sirius satellite ready, multi-colored display that randomly chages color(1,728), Dedicated subwoofer controls,and the MOST important part is that it reads SD cards! Those little storage cards that Digi Cameras use. No more carrying CDs loaded with MP3s or an Ipod that I have to connect. I can now have 1 GB of music in a disc that is about 1" x 1"
I have had an Alpine deck before, never had any problems, but this little JVC unit caught my eye...
So, bottom line, while asking for advice is good to get a "feel" for what people like, it really all depends on what model you think looks good in your car, you like, and that it has all the options you want...