Definitely one to watch! Even though this series seems to be mostly targeted at the mothers and daughters, guys can definitely watch it too. Yes, the lead cast are girls and it is classified as family/drama (which probably is the main reason guys shun away from this one), but let's be honest guys, you're not watching Buffy because of the great dialogs and the cute monsters ;) So looking at it that way, there's no reason not to watch this series also, because the leads simply are a treat for the eyes.
Anyway, on a more serious note, the dialog, that seems to attract so many of the non-believer's negative comments, is in fact not so unbelieving that some seem to believe. I've got several friends in fact that give a return on your speech just like that, OK maybe a bit slower, but not much. Yes, they (the Gilmore girls) go a slight bit over the top with the speed of the returns, and the weird references to people normally known only by literature professors are maybe a bit much. I think the whole slightly over the top thing was a known choice by the writer, to emphasize how it could be in a small town where everyone knows each other. The dialog only reflects this, people know each other, they know partially how the other person thinks, so they can have that speedy comeback. That's part of what I love about this series, the witty, sarcastic and quick dialog. I also realize that I should read up on my general knowledge to get all the small humor in the dialog. It's not like those sit-coms where they serve you the joke and then have a laugh-sign directed audience in the studio to help you laugh in front of your TV. With Gilmore girls, you actually have to follow the dialog AND have some knowledge about the world to get the jokes. And if you get the jokes, you'll laugh, for a long time.
The characters are simply great. All with their own quirks and sometimes weird behaviours. The acting could be better sometimes, but considering the time some of the cast members have even been actors, it's really good.
So, give the show a chance for at least one episode, you'll then notice you'll sit in front of the TV next week at the same time also ;)
I hope that I someday can get the whole series on DVD, even if it means paying big bucks to import it from the other side of the pond.