I have always been a Winamp user and it's because they have a simple easy to use interface that works well. Random and repeat functions have dedicated buttons right out in the open and easy to get to. A playlist that actually makes sense and doesn't require me to import my files into any database just to listen to them.
I never liked Alpine very much mostly due to how they looked; now I'm starting to realize that they are really good players with a solid interface. They are easy enough to use that anyone can get in my car and know how to adjust the radio without me explaining it to them. This Alpine actually has a touch strip below the display that is used very similar to the click wheel on an iPod. Not quite as user friendly but very close. The best part is that I can get to the random and repeat functions without having to go through a bunch of menus, it's part of the touch strip.
Now I just need to decide on a sub and amp combo and I'll be getting close to my ideal car stereo.