A 7950 will max out most games currently, while the 7870 may not. Get a 7950. Make sure to get one with custom coolers as overclocking will allow you to keep at max settings for a longer period of time. Btw, there is little to no way to future proof your system. The only advantage of getting a 7870 would be to take advantage of the savings now to buy a better, high end card in 3 years. By that time, your system may bottleneck a high end card anyways. Basically, spend what you can now, and upgrade when you need to upgrade.