UPDATED 3/31/11 9pm EST
I am sure there are more I missed. Thanks to those of you who told me of others, I will post the others as soon as I find pictures.
JAKQBanba dressed as an old lady.
Goggle FiveMiki dressed as a 'Prince' doll to contact a 'Princess' doll.
JetmanRaita from Jetman dressed as a geisha in order to fool a monster who was stealing young women's voices.
OhrangerIn Ohranger, Shouhei crossdesses as a woman as a secret undercover mission.
CarrangerA character who only appeared in Episode 23, a princess crossdresses as a construction worker in order to fool a monster. She was in cahoots with Naoki/Blue Racer.
GoGoVGoGoFive's Nagare crossdressed for a mission.
Gaoranger
Gao Black crossdressed in a wedding dress to fool Wedding Dress Org.
AbarangerYukito (AbareBlue) crossdressed in an episode.
Dekaranger In Dekaranger 26, he dressed up as a woman to get into an illegal fighting club - originally, he was there with Hoji, but was recognized as a Deka, and therefore had to dress differently to get in and not be recognized. And in Dekaranger 45, he dressed up as Swan to help get rid of a someone that was bothering her. Testu crossdresses to fool an Alienzer.
Magiranger vs. DekarangerHikaru and Tetsu crossdress to fool one of the monsters.
BoukengerThree of the boys crossdressed in a retelling of Cinderella that Natsuki did in Ep 26.
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Sakura crossdressed as a prince. Natsuki and Eiji were the only ones who didn't in that episode.
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I forgot that in the last episode, Morio disguised as Sakura as she went into space with Akashi.
Go-Onger All the males were rendered frozen and the girls hid them from the bad guys by dressing them as women as mannequins. Episode 38.
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Hanto dressed as an old woman's granddaughter, but it then turned out that the woman was a scientist from another dimension. Episode 27. Sousuke dresses up as an old lady or "Ba-san" in one episode when they were wearing disguised in the next episode, 28.
ShinkengerRyuunosuke (spelling wrong) crossdressed as a bride in Episode 8.
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In their post show special, they all crossdressed. I haven't seen the special so I do not know the purpose. Mako and Kouta as school boys, and the boys as girls, Genta was the only one who didn't wear his ranger-color of the boys, he wore pink.
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GoseigerHyde dressed as Nanami/Hurricane Blue for the Teamup special (they showed old teamups, by half-hour) that aired an hour before Goseiger.
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Eri as AbareKiller, for the same special, that aired for a couple of weeks.