I'm a fan of Asus: you get a lot for what you pay for and they're dependable laptops. The only con is that they don't sell off their website, so you have to go through third party sellers. It's not too bad, but sometimes it makes it harder to find a specific model.
Lenovos are pretty good, but a little overpriced.
skip alienware and razer: you're paying hundreds more for LEDs.
haven't had much experience with MSI, but people seem to like them.
if you're looking for a place to buy, check out newegg. However, if you're willing to shell out 1200 dollars, consider buildling your own pc. You can get a high-end PC with that much instead of a laptop that's a fraction of that performance. You might even be able to get it for a little less, then use the money you saved for a decent laptop for when you do need the mobility.