Aight, so first of all, I tend to like light, cheesy, fluffy entertainment, especially during the school year. That being said, SG1 is perfect, sort of.
Basically it's a little bit like star trek or something, except for the most part there aren't space ships--instead your four main characters bop in and out of this worm hole ring thing, and that's how they get around.
I'm about half way through the 2nd season right now, so I know there's a long way before the end--but that's all to the good, at least for now.
One caveat--at least now the show is pretty repetitious--you're not going to be able to really use your brain, and each episode isn't going to give you something new and exciting. But it's entertainment, pure and simple, with sort of a dry sense of humor.
And, well...I feel that this is a show that is um, greatly enhanced if you can manage to be obsessed with one of the main characters. For me, I really can't get enough of Daniel and his floppy hair. Which is getting cut soon. And then he's getting muscles *sob* not that there is anything wrong with muscles. Just muscles on Daniel.
Aight, so basically, if you like Star Wars/Star Trek/Firefly, etc. and want a light hearted sci-fi show, SG1 is a good place to start :) If you're up for anything more in depth, well you're probably not looking at sci-fi stuff anyway.