Parks and Rec is awesome, although I prefer Community to it, and it's not particularly geeky. There are geekier programs than Community, such as The Guild or The It Crowd, afaik, but they're not on american network TV, which is why I gave that answer.
Also, Community is really weird and I understand people who hate it. I, for one, think it's the best comedy ever, although to be fair, I haven't seen Arrested Development yet, or Seinfeld for that matter.
Edit : Well, Fringe is actually probably the right answer, now that you mention it.