Take a poll of everyone on what is the best brand and you will get 1000 different answers. Bottom line is that Most of the bigger names put together great rifles. Armalite, bushmaster, S&W, etc. all make quality arms. If you are buying a complete rifle expect to pay a grand plus or minus a couple hundred. However, consider building one. That is 2 to 3 hundred cheaper and a heck of a lot of fun to do.
Good Luck and welcome to Black Rifle disease!
When surrounded by your enemies, sometimes the best thing to do is to Shut Up!