The Office is by far my favourite show ever. I actually didn't watch it for years because I was upset that my beloved British version had been Americanised... and then watched one episode once, and have loved it ever since.

Parks and Rec is definitely the next one on the list for you. The first 2 seasons aren't great... but from Season 3 onwards it's just amazing, all the way to the end.

I also really like 30 Rock and Community.