As I said, it doesn't matter so much which kind you get, as much as the warranty. Best Buy's plan is about $300, but it covers anything that breaks. On my first I had the battery replaced once, and then the whole thing conked out. Refunded me the entire purchase price of the first for a new one. On my way to having a second battery replacement on this one as well as getting a new screen installed.
The one I have now is an HP zd7010. I don't recommend getting one unless you do a lot of programming; the wide screen is nice for the toolbars on the side of the Visual Studio environment. Having the extra width allows me to have a typical screen's width in between the toolbars when they're displayed.