Genmu Senki Leda

In both anime the heroine gets transported in another world where she finds out that she is a legendary warrior and that she must fight against an evil ruler. 

Another scantly clad sword wielding 80s fantasy heroine. What makes this particularly similar is the art style. Both OVA/movies share an obvious inspiration form the 1981 Heavy Metal Film, and the art style popularized by the magazine itself. 

One-off 80s OVAs with beautiful fluid animation, mecha action, cute girls, and great art. Their settings are very different tho, Dragon's Heaven is post-apocalyptic and Leda is set in a fantasy world 

The main heroines of these anime are extremely comparable in terms of bravery and choice of attire since they share similar old school high fantasy design philosophy and art direction of badass female warriors in bikini armors surmounting difficult hurdles to attain their goals. 

Main characters of those series are suddenly transported to a new, strange world. There they learn that they have some hidden power that is required to save this new world. Of those two "Genmu Senki Leda" has a more comprehensible story but "Unkai no Meikyuu Zeguy" is not bad either. It would definitely work much better as a longer series, tho. If you liked one you'll most likely like the other too. 

In both anime, girls are transported from their home into a new, fantasy world, and are chosen to become warriors and pilot mechs to defeat an ultimate enemy. 

Heroines fight against evil in worlds of fantasy and some advanced technology, and they wear skimpy outfits. They're also both 1985 OVAs. 

The visual style and general feel of both works is very similar. Both involve extended chase sequences with odd looking robots and moderatly cryptic philosophy masked by their manic tone. 

Both anime involve a girl who, during a scene in which she is determined to show her love for a classmate, is transported into a fantasy world, and must defeat a power-hungry enemy and return back home.