Freezing, Cross Ange: Tenshi to Ryuu no Rondo Recommendations
Girls who are physically different from the rest of Humanity and are pawns in the hands of forces beyond their control (and, for some part, understanding) fight with (apparently) no better hope than that of a painless death. Healthy amount of fan service. Dark mood. Enemies coming from The Outside.
However, Cross Ange is considerably darker and the scope is likely to be broader.
Both pairs act similarly to each other (Male MC is determined to be with Female MC) and although Female MC is of royalty, they're more of outcasts in the system and act as a recluse, although very adept in combat. Both shows have weird crap coming from the sky obviously harming humanity. In combat, the only way to fight is to get lots of skin showing.
Both series take place in a futuristic setting. Extraterrestrial beings exist and threaten daily life for the citizens on Earth. To combat these monsters genetically altered vixens, which in this case are Pandora (Freezing), Norma (Cross Ange), must enlist in the armed forces and fight. Death and destruction are routine for these soldiers who can't turn back to their old care-free life.
The females leads, Satellizer and Angelise are royalty with a horrific background. The pain caused from their past makes them shun others who try to be their friends. To make things worse, they are full of themselves, which causes jealousy among the other cadets
Both shows use female only characters for soldiers and both groups are forced to fight against their will against an enemy hardly know anything about.
Both shows incorporate special abilities Cross Ange has characters that whenever they sing a certain tune brings out the true power of their Para-mail, Freezing has characters that use special abilities due to the stigmata infused into their body. As a heads up Freezing has more characters in this category than Cross Ange.
Both shows have some Yuri overall Cross Ange features these kinds of things more compared to Freezing that shows bits of it here in their for both of