Minami-ke seems to be the twin sister of Today in Class 5-2. The most striking similarity is the "serious face" - i.e. when something weird/shocking/appalling happens, the faces aren't animated in the usual moe/loli (or whatever) idioms.
There's plenty of witless humor to go around, and a lot more pedo-fanservice as well.
The Minami-ke fan may be disappointed since there isn't really a Class 5-2 equivalent of Chiaki (there is a Chika, though), nor is there a Haruka, or any high school persona at that, but the cast is "diverse" enough to fulfill all the general archetypes as to not leave the viewer in rage at all.
If you enjoyed the in-class lighthearted, entertaining nature of Azumanga Daioh, then you might just want to check out Kyou no Go no Ni (aka Today in Class 5-2). Though still in-class based, this anime emphasizes the ecchi nature of 5th graders for entertainment. It's all in good fun, of course. So if you need a break from more complex animes, sit back and get yourself some of this anime for some laughs. Enjoy ~
Both revolve around one main character who is often the subject of unwanted (or wanted) sexual attention. And both are funny in the same sense of the main character being put in embarrassing situations.
While watching Kyou no Go Ni got the same feeling as watching Seto no Hanayome, the endless, good comedy, and expressions the main character makes are hilarious. If you enjoyed one you should watch another one too. Won't be disapointed.
Mitsudomoe is also a comedy with elementary? school children.
Similar style of humor. They also share the unconnected part-by-part presentation (each episode has multiple parts, which don't flow with each other but exist individually, focusing on a different "joke").
Neither of them have serious plots, mainly about the comedy.
Wow. I cannot believe that these have not been associated with each other before. Well, KnJ and Kyou no Go no Ni (Today in Class 5-2) both are centered around grade school and with plenty of loli panty shots to spare (for all of you that like that ;-D). They both have comedy based around sexual remarks and they both rock. Enjoy.