first time i got into computers i peed my pants every time i had to open one and i had no idea... building a computer is ridiculously easy compared to like .. 6 years ago..
dell is OK but they dont go for gaming machines( they like to put alot of intel cpus)... and you'd need a seriously good graphics card.. and all they have for good is a mediocre product at like .. 600 dollars because its PCI-E
alienware is the best .. but costs a fortune.. to get best gaming machine for a good deal youd really really have to build your own
if you decide to buy parts.. best site to consider is www.newegg.com
--i pay 2 dollars for shipping and gets here overnight
if you really want something built... best cheap gaming machine you can get would come from www.monarchcomputer.com
.. theyre pretty good about keeping their end of the deal.
but trully the best way to get the best hardware would be to build your own. and if you do watch out for certain web retailers.. they will scam you dry. www.resellerratings.com
is a decent site to find good reviews =D