An amazing show, written and produced by Aaron Sorkin.
It's a comedy/drama about a third-place late night sports show, called, aptly, " Sports Night."
The writing is excellent, (Sorkin also writes and produces "The West Wing," and wrote "A Few Good Men" and "The American President") and the cast is first-rate.

The two anchors, Casey McCall and Dan Rydell are played by Peter Krause (also in "Six Feet Under") and Josh Charles (also in "Dead Poets Society") respectively. The characters are best friends, and their inane conversations are great.

Felicity Huffman (excellent actress from David Mamet's Atlantic Theatre Company) plays Dana, the producer, and Sabrina Lloyd (also in "Sliders") plays her assistant, Natalie. Dana is a quirky woman, being a graduate of ladies' charm school and having many older brothers who taught her to love sports. Natalie is one of the most energetic and loveable characters, and provides social guidance for the rather clueless Dana.

Lastly we have Jeremy and Isaac. Jeremy is a great nerd character, played by Josh Malina (whose best known credits are Sorkin's other movies), who knows all sorts of obscure information and develops a romantic relationship with Natalie. Isaac, played by Robert Guillaume (who was Benson and was a voice in the Lion King), is the managing editor and resident curmudgeon.

All of the characters have depth and humanity, but are also funny and loveable. The show moves a lot; like "ER" and "West Wing," many of the shots follow people as they go hurriedly about their business. These two factors quickly suck you in and get you emotionally invested in the characters' struggles.

It originally aired on ABC, and met with gushing praise from critics, but didn't get particularly good ratings. When ABC let on that it wasn't going to renew the contract, HBO made motions at picking the series up (which is paralleled by "Sports Night" in the events of the final episodes). HBO changed their minds at the last minute, so the show disappeared for a while. Thankfully, Comedy Central has begun airing the old episodes (10:30am and 1:30am ET most weekdays). They have added a laugh track to some episodes (Boo. It sucks. The show works better without it) and broken up the commercials in different places (sometimes a bit awkward), but it's great to see the show on TV again.

UPDATE:
Yes, I was incorrect, the laugh track was originally in the first few episodes of the show aired on ABC, and not used in the later episodes.

All of Sports Night, both seasons, is now available on DVD. Last I checked, it was only about $50, which is WELL worth it.