my car came with a pioneer and i can't say a single good thing about that piece of crap. hard to use, worked really weired, ok sound. lots of do nothing features to make you want to buy it didnt' have some things you would want though.
I temporarly replced it with an alipine. not a bad unit lots of little things you can do with it that really does help the sound. and its easy to use, a little confusing at first but not bad.
Both of those are higher end stereos, probably $150 for the pioneer and $200 for the alpine (just rough numbers) I bought a cheap blaupunkt for my old car at costco and absolutly loved it. $100 for it. didnt' do much except what you wanted it to do. incrediable easy to use, awsome sound, it would read a cd that everything else wouls spit out. and the thing i REALLY liked about it was its time recal with the key off.
as soon as i can get another one i'll get a nice blaupunkt. they have some that will listen to your car, compare it to the stereo sound and cancel out the road noise. they also have some special thing in the radio reciver where its basically 2 recivers in one and somehow it makes the radio clearer. I don't know how it works, but it works good.
I can also say a lot of good things about their speakers too. the aluminum overdrive speakers put out an amazing sound. I had a total of $250 into my old cars stereo and it was one of the best sounding (quality wise) cars i've heard.