This is a pretty basic "clean" sitcom, though definitely the themes are more explicitly adult than let's say, ohhh, Seinfeld (to not be completely random). Extremely rewatchable in my opinion, you will catch many new things with subsequent viewings. I find it very funny, and JLD is in her prime here (perhaps excepting when she played a blind lawyer in Arrested Development).
You do not need to see Season 1 to enjoy this, I watched S1 later. S2 is the better deal, same price for way more episodes. Bear in mind S1 and S2 are the only seasons on pressed DVDs, the other seasons are on DVD-Rs only and are much more expensive everywhere.