So there are a TON of Male to Female Gender Bender Transformation manga out there, but I'd love to know of some good Female to Male. I've not read nearly enough and can't seem to fine, well, any on my own (which is kind of sad).

Samurai High School
1/2 Prince

Edit: These aren't transformation, my bad.

Ashamed as I am, I can really never remember the titles of what I've read, so even though I feel sure that I've read quite a few, nothing comes back.

Divine Melody. Actual, physical transformation, though she can transform back and forth at will. But her original gender is female.

Nononono

edit: Oh right, this isn't transformation either.

"I'll shut your mouth~~~~~ with mine~~~"

二息歩行

Boku to Kanojo no XXX - I believe the female and male lead switch bodies, but I might be wrong, read it a long time ago.

"...that ain't no unicorn" - Wakusei no Samidare

Normal City