Because the people at TokyoPop and Del Rey really don't know what they're doing when it comes to translating manga titles, here's a quick reference that you should use when requesting any of these manga:
-Karin - translated as Chibi Vampires
-Perfect Girl Evolution - translated as Wallflower (a.k.a. My Fair Lady, The Different Forms of Sunako)
-Kimi wa Petto - translated as Tramps Like Us
-Ikkitousen - translated as Battle Vixens
-Birth - Arm of Kannon
-Kiseijuu - Parasite/Parasyte
-Rave/Groove Adventure Rave/Rave Master = SAME THING.
Also, translated titles:
-Zettai Kareshi - Absolute Boyfriend
-Aka-chan to Boku - Baby and Me
-Hana Yori Dango - Boys Over Flowers (not quite accurate, but...)
-Kareshi Kanojo no Jijou - Kare Kano
-Count Cain - Godchild
-Ah! Megami-sama! - Oh! My Goddess!
-Ichiban!! - Number One!!
-Akuma de Sorou - The Devil Does Exist
I'm sure I missed a few, so feel free to add to this list any series that have different names when published in English. ^_^