I picked up some Boston Accustics SE85 5x7s for my door speakers after reading several reviews here on AFM. The first thing I noticed was a heavy treble bias, but also extreme clarity. I turned down the treble a bit to match the stock door subs, and I have been enjoying the sound for the past 6 months.
I am a musician and audiophile but have never spent serious money on a car stereo, just home electronics. However even with this simple setup the stock audio system has been a real pleasure.