@Cap'n:
Kururu's my favorite frog, with Keroro as a very close second. I think I like Tamama and Giroro about equally; Giroro's pretty badass, but I think Tamama's much funnier (and downright adorable). Dororo is a lame piece of crap. Paul is my favorite character overall, however.
Did you guys know that Keroro is a big parody of Japanese imperialism?
The helmets worn by the Keron forces were also worn by the Japanese army in WWII.
Also, apparently "Pokopen" is a degrading name the Japanese used to refer to China during WWII. That's why the anime changed it to "Pekopen." I dunno if it was intentional, but with the theme of the series, I'm assuming it was.
This is actually incredibly interesting. I got the World War II reference when we met Keroro's dad (who was hilarious, by the way) just from the way he acted and his getup, but I never thought about it to this extent. I find it funny how willing the Japanese are to condemn and make fun of their ancestors during World War II - I have a friend from there whose entire family is like that, despite the fact that the kid's grandfather was a Kamikaze pilot-in-training when the war ended.
And I don't hate Tamama to the extent that I do Dororo. I hated Dororo ever since I looked at the cover of a volume and had to go "what is this ninja frog doing on my space-alien comic book." On the other hand, I find with Tamama that I'd just rather be watching Kururu screw with someone's head, Keroro obsess about Gundams, or Giroro blow something up - it's not so much a matter of me hating him as it is a kind of "come on, get on with it" kind of thing.
Also, I can't remember who mentioned the Paul = Ken thing, but my friend told me that (in Japan, at least) Paul's uppercut attack is known as the "Paul Reppa", and Ken's best uppercut attack is known as the "Shoryu-Reppa." Funny all the little details crammed into this seemingly quite simple comic.