I saw that commercial too and was wondering as well. As far as the computers themselves go they are just fine. No brand name (Apple included) is ever as good as a custom PC, but as far as brand names go Dell is a bit better than average. Dell is pretty big, they do supply computers to many banks and gov't offices and schools. Warranty support is very stong with them...provided that your computer is still under warranty. Doing upgrades like memory adding HDDs and optical drives doesn't void it....unlike some other companies (Apple again).
As a computer technician I am speaking from firsthand knowledge, not opinion.
Opinionwise that commercial is a bit out there, but better than that guy that would always say "Dude, you're getting a Dell"
I know I'm not the only one that wanted to punch that guy in the nose!