I watched the “Clone Wars” movie when it was first released in 2008. It is probably the worst movie I've ever seen in theaters. My roommates (including Ryan H.) and I were the only ones in the theater, and we spent the whole time mocking it.
As such, I was hesitant when I heard about the similarly-named show that was to follow the movie. Fortunately, “Clone Wars” the show is much better than “Clone Wars” the movie, and even better than the prequels. The terrible comedy of the prequels is much improved and/or diminished. Anakin's angst has disappeared, replaced by a pragmatic drive. The philosophical messages that are confused in the movies become much more focused.
For the uninitiated, the “Clone Wars” show is a series of short stories that happen throughout the war. In the early seasons, each story arc usually lasts between one and three episodes. While most center around the main characters from the movies, many introduce new characters. The show brings the Star Wars universe to life in a way that the movies couldn't, allowing us to see various worlds, characters, and creatures across the galaxy.

Also, sometimes Jar-Jar is in it. You can't win 'em all.
A breath of fresh air in the series is the humor, which has noticeably improved from the prequels (and the “Clone Wars” movie). The oft-maligned stupidity of the battle droids works well in this cartoony setting, and there's also a real threat with which to contrast them: the new-to-the-show commando droids, which are used effectively throughout. Similarly, the in-jokes in the series take a cue from the prequels in their references to other movies in the saga, but the writers do a good job of walking the line between cheeky homage and overdoing it (keep on the lookout for “I have a bad feeling about this,” which appears in just about every episode).
While there are many things to recommend, Season One of “Clone Wars” really captured my attention because of the unexpected themes, and one theme in particular, that the creators present throughout the show. There is a lot of focus on the clones – how others view them and how they view themselves.
In the show's very first episode, Yoda is trapped on Toydaria with three clone troopers. While the three troopers see themselves as identical, Yoda sees their uniqueness through the Force. Often, clones use the refrain that they are “just clones,” seeing themselves as expendable sacrifices for a noble clause. Their extreme fatalism is countered by the Jedi, who clearly value the clones and see them as people – a marked philosophy shift from General Grevious, who destroys his minion droids at every opportunity.

He also is constantly escaping from various ships that explode around him.
Another big theme is the constant emphasis on the cost of war. In “Defenders of Peace,” Ahsoka and Jedi Ayala Secura set up camp on Maridun, a planet of Lumen pacifists. The elder is entirely devoted to pacifism, even if it means their lives. The youngsters, however see that the Separatists will destroy their village without a thought. Eventually, the Lumen do fight back, and the Republic gains the advantage, but in the closing moments of the episode, the elder Lumen wonders what the cost of the victory was. The tribe's values were violated, costing them their identity as a people.
While this is not my favorite episode, it speaks to the larger point the show's creators drive at: doing what it takes to win a war changes the culture, and the people must always be wary that war will harden their compassion and ability to uphold democracy. The ends do not justify the means.
Much of this season is not so serious. There is one arc entirely devoted to R2-D2's heroics, which is tremendously fun. The season finale, “Hostage Crisis,” introduces Cad Bane, a badass bounty hunter with the best voice (it's a sweet mechanically enhanced sound effect) who breaks into the Senate to free Ziro the Hutt (otherwise known as Jabba the Hutt's gay uncle; see Ryan Vanasse's review of the “Clone Wars movie for more on him).
There were several elements from the prequels that are noticeably absent in this season. The Padme/Anakin love story is barely present (which is fine by me). Palpatine's puppetry of the war is also faint at best, as well as Anakin's journey to the dark side. These latter points are somewhat disappointing, as they are some of the more engaging stories of the prequels, but overall the first season of “Clone Wars” is well worth watching. If you're a Star Wars fan and haven't watched it yet, give it a try.