Any kind of TF as long as long its related to fighting.
Shkugan no Shana
Shana running towards the enemy as her long hair turns smooth blazing fire, at 34-41 second mark.
Shana growing flaming angel wings,at 54 second mark:
http://uk.youtube.com/watch?v=RwF2KSAao4U
Black cat and To love ru`s Eve and Yami with her body tf.
Mai otome robe transformations.
I guess you can count the Super Saiyajin TFs.
Basically as long as the TF has the intention to fight its fine.
Hair TF`s, body tf`s and clothes TF`s seem the most common.