ASUS is so much better.
that's... primarily a mobo manufacturer.
Also, if you can pay it, Alienwares are solid. My friend has had one for two and a half years and it's never given him any problems and he can still play most modern games on it. They're good computers, just a tad expensive.
Usually, yes.
I own an $850 computer that I built myself with my own money that I worked for and saved and I'm 15 and my parents are by no means rich (by American standards, of course).