I'd say it's sort of a toss up between number 2 and 3. #3 has the (theoretically) slightly faster processor and the vid card is the better of the two. However, it has less RAM as default (which, honestly, is very easily upgraded and not that expensive to do) and the processor is an Intel, whereas @2 has the AMD... which, in my opinion, is likely to run you better in the long run. However...
While the RAM and the processor would be upgradable in both, the video card is very likely not. Processors and RAM aren't that expensive to upgrade. Vid cards are usually integrated, so what you get when you buy the laptop is what you're stuck with (to my dismay.) In my opinion, based on that, I'd buy #3, and see if you can at least swing a RAM upgrade to get that last gig.