Queen's Blade Rurou no Senshi: The manga adaptation of the first anime season, but with some differences in plot.
Queen's Blade Hide & Seek: The same as the above, but the plot is seen from Elina's POV, and many different stuff from the original plot of the anime. Also includes the plot of the second season.
Queen's Blade Rebellion Zero: An interquel that takes place between the events from the OVAs and the regular Rebellion series, but with a more darker plot.
Queen's Blade Rebellion: The Princess Knight of the Blue Storm: The manga adaptation of the Illustrated Stories (not from the anime) who expands some unexplained stuff from them.
Now Which One Was That Voice: In a odd inversion of this trope, Owen's Japanese voice isn't listed in the final episode cast list and, to this date, it hasn't been explained why he's not listed in the cast. Averted with his English voice actor.
Played straight with Delmore's English voice actor.
Recycled Script: The script of the second Beautiful Warriors OVA recycles the plot of the Queen's Blade Bitoshi Retsuden: Adventure of the Vagrant Warrior book who originally starred Leina and Claudette vs Nyx. They're replaced by both Nowa and Alleyne instead, and the battle against Nyx is in a beach in the OVA rather than a volcano like in the book.
Most of the female cast of the series also worked in the Japanese dub of Cold Case. The hilarious part of this is most of them voiced many of the victims or murderers of that series. Even more hilarious is the fact that Atsuko Tanaka (Claudette) dubs the main protagonist, Lilly Rush, whose main job is solve those murders.
By sheer coincidence (or maybe not), most of the female cast also worked in the Touhou's few voiced works:
Yoko Hikasa (Dora, Hana and Junko) voiced Marisa Kirisame in Fushigi no Gensokyo 2: Miracle Party.
Kaori Mizuhashi (Elina and Lou) voiced Kaisen Ibaraki in Fushigi no Gensokyo 2: Miracle Party.note Oddly enough, she didn't voice Parsee Mizuhashi, despise Elina and Parsee are very similar in personality.
Ayako Kawasumi (Leina) voiced Gwendolyn, who shares her background, but her personality mimics Claudette instead.
Mamiko Noto (Tomoe) voiced Mercedes, whose personality is more akin to Nanael, being both winged beings with annoying personalities.
Sayaka Ohara (Melpha) voiced Griselda, who shares Maria Vance's background (being the respective dead relative who everyone idolizes, except in Odin Sphere, she voiced the dead elder sister)
Takako Honda (The Head Archangel) voiced Queen Elfaria, who is also a winged being and a Big Good, except she dies early in the game, and being an authority figure for another winged being (Nanael in QB and Mercedes in OS, being the latter her daughter)
Schedule Slip: Of the American DVDs. And also Queen's Blade Rebellion, since they haven't posted more episodes due to Hobby Japan trying to promote the QB gamebooks in the U.S., but it will resume on December 2011.
It also happens with some gamebooks (Painkiller Kotone and Sen Tokugawa's ones are the most notorious examples, since their gamebooks were announced since 2011 and they haven't released yet, even when Kotone appeared in Queen's Gate Spiral Chaos). In fact Hobby Japan is really notorious for doing that, and not giving any explanations.
What Could Have Been - Originally, the Queen's Blade Spiral Chaos game was planned as a multi-series crossover game Super Robot Wars-style, but using non-mecha series (besides Queen's Blade, other anime series were planned to appear) but it wasn't possible those series to be included, due to the authors and companies being reticent to allow their characters being crossed-over with other characters from other series. The sequel, Queen's Gate Spiral Chaos is the closest thing to the original idea Banpresto was able to get and still they weren't allowed to use Kasumi from the Dead or Alive series and she's replaced with both Wonder Momo and Noel Vermillion instead.
It's very possible the reason why Kasumi wasn't included is because Tomonobu Itagaki (the former Dead or Alive director) trashed Tekken (a Namco Bandai franchise) really hard and it's possible that Namco Bandai doesn't want Kasumi being crossed-over along with Lily from Tekken
Eilin was intended to use a ribbon instead of her katusha.
Siggy has two different previous designs before her definitive one: One was more Stripperific and the other was more conservative instead, and used a kusarigama rather than her cross-chain.
Huit used a hat, rather than her leaf ribbon, and Vignt used tighter shorts rather than her skirt.
Tarnyang was originally planed to use a spear, rather than her Chinese sword or jian.
Branwen is maybe one of the characters with the most changes before her final design: She originally was planned to have short hair, other using a horned tiara and another one with another tiara with bigger horns.
Word of Dante: A minor one regarding Claudette: Fanon normally gives her the Vance's last name, despise Claudette being a bastard daughter and as such, she can't have any nobility title and she's basically a glorified servant for Count Vance. In canon, only Leina and Elina Vance (the biological daughters of the Count and Maria) have last names and they are addressed as such in many other works, including in the animated adaptation.