For us mere mortals on a $500-600 range, the Brinkman Pro series is very nice and solid.
I bought a 6 burner, cast iron burners, brass side burner, infra-red back burner, very well layed out tool tray underneath and even came with a built in sink.......NICE
I like the 6 burners, and not just for tons of meat, but you have more heat control and can do indirrect cooking on it too. I think I paid $499 for this.
Pro Series 2720 with Rotisserie
http://www.brinkmann.net/Shop/Detail.aspx?category=Outdoor+Cooking&subcategory=Gas+Grills&sku=810-2720-1&id=1323