Could someone tell me which one is better?

The best buy computer has a faster processor. Has more Ram and a bigger hard drive. I'm not a big fan of Best Buys because of their return policy but you should jump on that computer. Your getting more computer for your money. I checked dell and the price beats dells price for the same computer. In fact when I saw you question I almost bought the best buy computer but they where sold out. If you can still get it. Go for it.