This is such an easy question. I was answering it (without being asked) last night with a friend over dinner.

Major female characters who are strong, are willing to go after what they want, are unapologetic about who they are, and who are interesting to watch.
I never get squicked. Seriously, I haven't been even once.
The stories are, for the most part, well told. I can only think of one episode that the storytelling didn't work for me and the show is now in its third season.
Issues like race and disability come up and don't make me want to shoot anyone. If anything, I usually react with, "ooooh, that's an interesting choice."
Personally, I like the law component of it but I think the reason it is popular overall is because of the character development and interaction.
I don't know that this happens every episode but they frequently just have these gems of moments that you wouldn't see on another show.
It is filling a niche for me in that I can watch it without worrying about sudden fail hitting me upside the head.
People being clever. People with foibles. People taking responsibility. I like all of that.
AND OMG I can't wait to see where the plotline goes after last week's ending.

I recommend it. Highly. Start at the beginning.