The Geforce 410M card is rather weak. I'm not sure how happy you would be with that card. It could only play SC2 smoothly on low settings, for example. It depends on just how "light" of a gamer you are. If you really don't play that many games or if you don't play the newest games, then you might be okay with it. It is just barely a step above the Intel HD 3000.
Of the machines listed so far, it seems the Lenovo is the best bet even with its AMD processor. AMD processors are fine for what you're doing and cheaper than Intel ones so more money is likely going to the graphics card. It has the most powerful card of the three computers we've seen for this budget and can play SC2 up to medium settings, although even still it might struggle with Skyrim on low settings
Here's a thread with some more suggestions: ~$500 laptop
The only issue I've seen with the computers mentioned in that thread is that none of them are certain that they have the Kensington lock you need. There are some good ones in there though. The HP is very powerful for the price, although that is refurbished.
Well, I would suggest to options:
1. Wait. new gpus and cpus are coming out now.
2. Try to find another 50$ and get the [cut-down] Lenovo Y570 with Intel I5-2430M cpu, GT 555M gpu, 6GB DDR3 memory and 750GD HDD for 700$ link
you have more options, like the HP dv6t
you can configure it with a radeon 7690M. With the 30$ discount coupon you can find on the web right now it will be about 650$.
Processor: Intel® Core™ i7-2670QM (2.20GHz, 6MB L3, 1333MHz FSB)
Operating System: Genuine Windows 7 Home Premium 64 - English
Hard Drive: 500GB, 5400RPM Serial ATA 2.5" Hard Drive
Total Memory: 8GB (2 X 4GB) PC3-10600 DDR3 1333MHz SDRAM SODIMM Memory
Display: 15.6” HD WXGA (1366 X 768) LED, W/ 2.0 MP Camera
Graphics: NVIDIA® GeForce® 555M
Optical Device: DVD Recordable 8x Max Dual Layer
Keyboard/Pointing Device: Industry Standard Touchpad