crossdressers (my fav, though top of my list would be "guys fucking crossdressers". only when a boy is TOTALLY convincing... it is knowing that behind the clothes and makeup, the boy has "shamefully", a natural potential to be soo feminine).
shemale solo (very similar to "crossdressers"... only if convincingly "female", although the idea that alot of work went into the appearenace subtracts from the disdainful innate potential for femininity).
guys fucking shemales
shemale on shemale (Generally I prefer a masculine presence to emphasize the femininity, though am really turned off by masculine shemales. I love a line of shemale fucking shemale, fucking shemale etc...)
shemale on female (too mundane)
shemales fucking guys (this utterly repulses me, a masculine body performing feminine activities is a real turn off.)