Well to be more specific, gender benders where it's the guy -> girl.. Doesn't matter if it's just crossdressing or they become a girl totally. I like both 😀
Kinda had enough with girl -> guy for now

Ones that I liked (Out top of my head atm)
Kakumei no Hi
Click
Pretty Face
Yubisaki Milk Tea

Family Compo by Hojo Tsukasa
X+Y, third story in A, A' by Hagio Moto. There's also Marginal by the same mangaka, but that one is yet to be scanlated into english (though the summary does exist).

[img]http://i75.photobucket.com/albums/i285/yuuri097/Hanashizume_no_Utage.gif[/img]

Maybe Ai no Shintairiku... and technically not gender bender but Croquis subplot is he wants to be a girl so he could have normal relationships.
Inter Sexuality could be counted as it too, so could Hourou Musuko.
These aren't exactly just crossdressing or transformation for kicks or anything, the last two especially are more serious in tone.

I second Hourou Musuko.

Penguin kakumei maybe? It has both, and very cute.
W juliet has both too, I think... Haven't read it myself yet~

Edit:
Nicoichi
Shion no Ou has one.
Ichinensei ni Nacchattara erm...

Hrodulf and Bjornolfr, you will not be forgotten.
[img]http://i411.photobucket.com/albums/pp199/SyberAngelGabrielle/couplesig.jpg[/img]
[color=black]And if the world were black and white,
you would be my rainbow in shades of grey.[/color]

Click 'n Play!

If I had a fantasy self, it'd be a tentacle monster.

Hmm, you could try one of these:

Kashimashi - complete male to female transformation
Seijou Kouchakan no Jijou temporary transformations
Maria Holic one of the leads is a male cross dresser (scans are just getting started)
Blue Drop - Tenshi no Bokura - male to female transformation and lots of cross-dressing.

Tree + Taco = Tree taco.

Well ther ar´n´t many to begin with and the good ones are already named
all i miss is
Gacha Gacha - Secret ok that Starts at Volumen 6 from Gacha Gacha and its male to female

For the sane people I am insane,for me the sane people are insane!

Family Compo is not really to my tastes >.>
Kashimashi was ok, but the plot was kinda plain to me.
Shion no Ou, how different is it from the anime? I watched the anime but wasn't sure if it's worth reading the manga.

Haven't read the other ones that are mentioned, so I'll check them out.

Thanks~!