Like most people, my first exposure to the world of Excel Saga came with the wacky 26-episode anime from 1999. You should know before you begin the manga that the anime and the manga are completely different monsters. While the anime revels in over-the-top insanity, the manga is a lot more down-to-earth. Characters and situations are presented in a much more realistic fashion. Rather than parody of anime tropes, the primary comedic focus here is social and political satire. It gives a skewed look at what an actual attempt to take over a modern Japanese city would look like.
The basics of the anime are present, of course. Il Palazzo is still the leader of the secret organization of ACROSS. Excel and Hyatt are still his (enthusiastically hyper and dangerously ill, respectively) trusted female agents who carry out missions to hopefully bring about the conquest of F City. Opposing them are Kabapu and his handful of disinterested average joes (and one jane). The brilliant Dr. Shioji's Ropponmatsus generally do most of the fighting. Like the anime, Excel and Hyatt do live poor for most of the series, and most of the humor in the early volumes comes from them being forced to take part-time jobs to sustain themselves (during which they typically observe some form of corruption or general economic debauchery). Things you won't see in the manga that you'll remember from the anime include Pedro, Nabeshin, That Man, the Puchuus, and more.
Over time, the series begins to shy away from comedy, and the development of an ongoing plot takes first priority. Many characters are introduced who never appeared in the anime, such as Umi, Miwa, and the spoiled, beautiful Elgala, a third ACROSS agent frequently foiled by Excel's thrifty lifestyle. Fanservice is kept to a minimum until somewhere around her introduction (although it never reaches the heights of what the anime achieved in that regard).
Rikdo Koshi's art is really nice, with lots of fine details. I wish I could see it larger than in the usual manga size, I feel like a lot of subtleties are lost on Viz's tiny pages. The characters are Excel Saga's high point. The cast is really diverse and well-written. None of them are quite normal, but their personalities are so well-rounded that they feel like someone you could actually meet anyway.
Some people won't like Excel Saga because it's so downplayed and subtle compared to the anime, which I guess is understandable. I can't really recommend this to everyone; even without factoring in the differences from anime it's still very different from any other manga I've read, comedy or otherwise. There's no romantic subplot, and there aren't any schoolgirls doing random/cute things. It's just an irreverent and really likable story about conquest, power, and the people who seek it. If you're looking for a humor manga that's a little different from the usual stuff, check this out.
