Ten Little Gall Force

Both are fictional "Making Of" mockumentaries for their respective shows. The characters have actors, there are bloopers and outtakes, slapstick comedy situations on the set, and a film crew. Both are well made and seriously funny. For Maria-sama, such a special exists for each season, for Gall Force only for the first three movies. Otherwise, the actual shows this specials belong to are very different. 

There are no bloopers in anime, right? There can't be any since everything is drawn and not filmed, right? Wrong! Some anime were actually filmed and the characters are just actors. And as it is with any movie, bloopers do happen when filming an anime. The Choujo is stand-alone feature, where at the end you can see some of the scenes that went wrong. Ten Little Gall Force is the "making of" for Gall Force movie franchise. You can see interviews with the actors mixed with some of the bloopers that happened during the filming. 

Both are short parodies of older mecha series. Both are comedies featuring chibi versions of characters from parent series. Both are not to be taken seriously. 

Both of these parodies are done by AIC and Movic, the creators of the shows involved in the parodies (no connection otherwise). If you like super deformed characters, or just plain silliness, these shows are for you.