Higurashi no Naku Koro ni Kira

Both anime are considered comedies based off a serious series celebrating a milestone. Both series features characters from their respective works and are a funny watch that brings out hilarious comedy to the viewers.  

This is mostly for the second episode of Higurashi: Kira -- but if you like this one magical girl AU spinoff OVA of a gory and violent anime, perhaps you will like this other one. 

Both are parodies of their respective series, which are very serious and dark in every way possible. Also, both are very funny and don't have sense at all. If you liked the main series, you will like them. 

Magical Girl parody. Higurashi Kira and Nisekoi S2 do have their magical girl parodies, that take the same generic plot route. You can expect the transformations to be similar to the general type and the battles too. Would recommend the original series if you are interested in them too. 

Full Metal Panic? was less serious than the Higurashi series but it did have it's suspenseful moments. Both of these series are mostly humor with fan-service... and a tiny bit of plot thrown in for spice. 

To me both "High School of the Dead: Drifters of the Dead" and "Higurashi No Naku Koro Ni Kira" are a bunch of what if's to the whole story far from their original intention. Higurashi No Naku Koro Ni Kira, however is a type of OVA w/ multiple short stories, while HOTD Drifters of the Dead only focuses on one story. One similarity between the two is the use of fan service, however HOTD Drifters of the Dead does obviously contain a much more mature type of this fan service. 

These OVA series are part of franchises that have nothing to do with magical girls, yet decided to go ahead and take their characters and do a magical girl parody anyway. They are fun as silly AUs of their original source, appreciating the characters in new contexts, as well as enjoyable for seeing the magical girl genre poked fun at. 

Both series deviate from more serious parent stories to produce self-parodies (and parodies of other things). Both series also feature magical girls and fanservice.