If you have the money to buy either, go with the first one. The processor in that one is faster, but in games should be comparable to the second listed system.
The socket for the first one is newer however, and will probably enable you to upgrade better further down the road. The PSU is a bit on the low side as far as wattage is concerned, but it should be able to handle the system as listed. It won;t have much room for anything more powerful, but I;d still go with the first, if only because it uses the new socket. Socketchanges are a lot more annoying and expensive than a PSU swap.