Mainly, that I eat up both programs with a spoon. They are both so light, so fresh, so speedy and zeitgeist-y. They are both addicting. When I watch either show, I am drawn in so quickly because the dialogue drops so fast and there are tons of in-jokes. Oh, and there's so much eye candy each scene is popping with it. Four friends take on L.A., much like four friends taking on NYC.
Boys will be boys, right? I mean, Entourage is very obviously created to appeal primarily to a straight male audience, with all its t&a and constant video game playing. Yet still, it manages to appeal to a "sophisticated" lady like me...not to toot my own horn here, but I think that has something to do with how smart the show is.
Those four guys, Vince, Eric, Turtle and, of course, the luggish Drama, are so danged believable. We all know crews of dudes that are just like them and operate just like them. It's fun to be "in" with a group of friends like that, just as it was when Sex and the City was on and I loved watching the gals sit around the coffee shop table exchanging witticisms.