The 'top half dozen' are actually pretty expensive. Depending on how much gaming you will be doing and how high of quality you want it, here is how you should go about determining which one to get
A) Pick a few laptops that are in your price range and have dedicated graphics cards in them
B) look up your card here and note the scores:
http://www.videocardbenchmark.net/gpu_list.php
C) If you want to determine what the score means, and how that will translate to gaming, then do a youtube search on the graphics card itself and there will be plenty of people who have taken screen cap vids of them playing a game with that card.
If you do it this way, you will have a better chance of getting what you want
Good luck!