Note that this thread is already mostly out of date. I now only suggest laptops with Sandy Bridge CPUs.
These are the cheapest laptops I could find that have a certified graphics card. I don't actually endorse any of these, just providing them for reference. If you can find one any cheaper, feel free to beat my "low score".
Notes: Almost all manufactuer's websites were impossible to navigate. Toshiba and Asus make some of the top quality laptops, but their websites are literally impossible to find what you want. Dell wasn't really any better. I didn't even try HP or Lenovo (see below). The only website that made this easy was newegg.
14+"
$1,218.99
HP EliteBook 8440w (WZ314UT#ABA) Notebook Intel Core i5 560M(2.66GHz) 14" 4GB Memory DDR3 1333 320GB HDD 7200rpm DVD Super Multi NVIDIA Quadro FX 380M
http://www.newegg.com/Product/Product.aspx?Item=N82E16834157483
$1,179.99
HP EliteBook 8440w WZ314UT Notebook PC - Intel Core i5-560M Processor 2.66GHz, 4GB DDR3, 320GB HDD, 14" Display, Windows 7 Professional 64-bit, Silver
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=6711393&CatId=4939
$1,464.99
HP EliteBook 8440w (WZ315UT#ABA) Notebook Intel Core i7 640M(2.80GHz) 14" 4GB Memory DDR3 1333 500GB HDD 7200rpm DVD Super Multi NVIDIA Quadro FX 380M
http://www.newegg.com/Product/Product.aspx?Item=N82E16834157484
15+"
$1,268.99
HP EliteBook 8540w (XT903UT#ABA) Notebook Intel Core i5 560M(2.66GHz) 15.6" 4GB Memory DDR3 1333 320GB HDD 7200rpm DVD Super Multi ATI FirePro M5800
http://www.newegg.com/Product/Product.aspx?Item=N82E16834157485
$1,399.99
Lenovo ThinkPad W510 4319-64U Notebook PC - Intel Core i7-720QM, 1.60GHz, 2GB DDR3, 320GB HDD, DVDRW, 15.6" Display, Backlit Keyboard, Windows 7 Professional 64-bit, Black + Quadro 880M
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=7025541&CatId=4939
$1,399.99
ThinkPad W Series W510(431964U) NoteBook Intel Core i7 720QM(1.60GHz) 15.6" 2GB Memory DDR3 1066 320GB HDD 7200rpm DVD±R/RW NVIDIA Quadro FX 880M
http://www.newegg.com/Product/Product.aspx?Item=N82E16834146919