The only brand that I use when I paint cars is PPG. They are one of the top brands at a reasonable price. Now there is also House of Kolor that specialize in Candy paints that area good brand too. They are kinda pricey tho.
If you want to see what it PPG looks like go to this wesite and look at a 52 Chevy Bel Aire.
www.3dautobody.webs.com