The pilot is a good one, but NOT the best early one to watch to pick up the feel. Try Charlie Wants An Abortion. That should definitely have enough horrible stuff to give you an idea of what the show is.
And Jihad wasn't one I liked too much at first, but is actually one of my favorite episodes by now. Same for Gun Fever. Watching it and just enjoying how much [spoiler]they hammer in that Dee's boyfriend was the theef[/spoiler] just keeps getting funnier to me. As well as Charlie's hilarious relationship with his landlord. And Underage Drinking is awesome, it was the one that made me really love the show.
My bottom 5 would be (in order from worst to better):
The Gang Gets Racist, Dennis and Dee Get a New Dad, The Gang Exploits a Miracle, Charlie Got Molested, and Gang Finds a Dead Guy.
Top 5: Mac Bangs Dennis' Mom, The Gang Runs For Office, Underage Drinking: A National Concern, Hundred Dollar Baby, and Charlie Has Cancer (Dude, is that a hate crime?)
"You just had a glue OD, and those are pretty regular in my life. So here's another lesson: don't huff too much glue, or your night sucks."