There are some things out there that are beyond belief, reason, and most of all, sanity. Excel Saga is one of these things. The continuous stream of visual/verbal gags, inside jokes that are also funny from the outside, and such wonderful and irreplaceable characters such as Ilpalazzo, Nabeshin, and (most of all) the Puchuus make Excel Saga one very interesting trip.
There is so much to laugh about in this series, and so much of it is so nonsensical that it makes sense. I watch and I watch, and though I know what's going on, does anyone *really* know what's going on in the series? Hrm...but it doesn't matter. It's all about the jokes and giggles, not some answer to the Deep Philosophical Question of Life. Go watch Eva or something if you want that.
However, Excel Saga is still smart and funny, which is much more preferable than brainless funny anime like DiGi Charat. I firmly believe that watching DiGi Charat likely kills brain cells.
The only bad thing I have to say about this anime is I did not like the English dub at all. Jessica Calvello wasn't so great as Excel...to put it mildly. What can I say? I'm not a fan of the "nails on chalkboard" effect.
Other than that, watch. Watch Excel Saga.