If you could give a legendary a gender...

[Rainflower]

Most of them fits as males, but I think Suicune, Mew, Shaymin (Land Forme), and Articuno should be female.

I consider Virizion as female-looking as well, but somehow it fits as a male Pokemon better

 

[Golden Warrior]

Most of them fits as males, but I think Suicune, Mew, Shaymin (Land Forme), and Articuno should be female.

I consider Virizion as female-looking as well, but somehow it fits as a male Pokemon better

I always thought of Virizion as female. But, it's all opinion... opinion, opinion.

 

[Echidna]

I'd make Lugia a male, and Ho-Oh a female.

 

[Atomic Pirate]

The 3 Lake Guardians, Meloetta, Palkia, and Jirachi should be female. The 3 Beasts, Dialga, Giratina, the Musketeer trio, the Genies, and Arceus should be male. The Golems should stay no-gender, because the Golems aren't really an actual life form, just an element or substance. Mew shouldn't have a gender, as it contains the DNA for all Pokemon, and not all Pokemon are the same gender. Same with Mewtwo, because it is a stronger clone of Mewtwo. For the other legendaries, I really don't know.

 

[mewditto]

I'll just do an entire list:

Zapdos: Either?
Moltres: Male
Articuno: Female
Mewtwo: Male
Mew: Never thought of this one really... But I guess male.
Mewditto: Male :)
Legendary Beasts: Either or Male
Ho-Oh: Male
Lugia: Female
Celebi: Female
Regi's: I don't think it's possible...
Latios: Male
Latias: Female
Groudon: Male
Kyogre: Male
Rayquaza: Male
Jirachi: Female
Deoxys: Female?
Azelf: Male
Mesprit: Female
Uxie: Female
Dialga: Male
Palkia: Female
Giratina: Male
Darkrai: Male
Cresselia: Female (derp derp)
Manaphy: Male
Phione: Male
Heatran: Male
Regigigigigigigigas: Male
Shaymin: Female
Arceus: Not possible. Pfft.
Victini: Probably Female
Cobalion: Male
Terrakion: Male
Virizion: Female
Thunder Trio: Males
Zekrom: Male
Reshiram: Female

 

[~*!*~Tatsujin Gosuto~*!*~]

Ummm a few of my gives:

Articuno Female
Giratina Female
Shaymin Female
palkia Female
Mewtwo Male
Zapdos Male
Darkrai Male
and Regice Female


:t354:TG

 

[Eucliffe]

Articuno, Zapdos, Moltres - Male 50% Female 50%
Mewtwo - Male
Mew - Female

Entei, Suicune, Raikou - Male 50% Female 50%
Ho-oh, Lugia - Male 87.5% Female 12.5%
Celebi - Male 12.5% Female 87.5%

Groudon - Male 87.5% Female 12.5%
Kyogre - Male 12.5% Female 87.5%
Rayquaza - Male 50% Female 50%
Jirachi - Male 50% Female 50%

Mesprit - Male 12.5% Female 87.5%
Azelf - Male 50% Female 50%
Uxie - Male 87.5% Female 12.5%
Rotom - Male 50% Female 50%
Dialga, Palkia, Giratina - Male 50% Female 50%
Phione, Manaphy - Male 50% Female 50%
Darkrai - Male 100% Female 0% (how does it make sense that its enemy has a static gender and Darkrai doesn't?)
Shaymin - Male 0% Female 100%
Arceus - Male 50% Female 50%

Cobalion, Virizion, Terrakion - Male 100% Femake 0% (based off the three Musketeers, so yeah)
Reshiram, Zekrom, Kyurem - Male 50% Female 50%
Keldeo - Male 100% Female 0% (same as the Musketeers)
Meloetta - Male 0% Female 100% (how can this thing even be male Idek)

All others keep their current genders (and the ones that don't have them remain genderless).

 

[Oryx]

Meloetta - Male 0% Female 100% (how can this thing even be male Idek)

Spoiler:

I find it interesting that Mewtwo has a male voice in the anime, and I'm pretty sure they refer to it as a he at least in the manga if not the anime, but it's genderless.

 

[Golden Warrior]

Regice Female
:t354:TG

I hate to disagree with you. But, Regice is a golem or whatever they are called. So, it really shouldn't have a gender.

 

[Clark]

Yin and Yang are associated with the female and male genders, respectively. Just going by what they were designed to represent, Zekrom would be female, and Reshiram would be male. Using the same logic, the Musketeer trio would all be male, since they're all based on male characters.

 

[Pokemon Trainer Touko]

Victini, Mew, Celebi, Articuno, lake trio, Suicune, Virizion and other cute legandaries should be female. :3

 

[Satoshi Ookami]

Yin and Yang are associated with the female and male genders, respectively. Just going by what they were designed to represent, Zekrom would be female, and Reshiram would be male. Using the same logic, the Musketeer trio would all be male, since they're all based on male characters.

Finally someone who mentioned this =D
Even though Reshiram and Zekrom are genderless their gender was decided when the fact that they represent yin & yang was revealed =)
So Reshiram must be male and Zekrom female.
And since Kyurem represents wuji, it must be genderless. =)
My opinion =)

 

[The Nightmare]

Most of the pokemon are male than female the only one I see as female is reshiram, celibi, latias and mew.

 

[Satoshi Ookami]

Most of the pokemon are male than female the only one I see as female is reshiram, celibi, latias and mew.

I just explained why Reshiram is male xD
Anyways Latias really is female so you shouldn't mentioned her :D

 

[Myles]

Male:
Mewtwo

No Gender:
Regis
Deoxys (since it's a virus)

Varying Gender:
Everyone else

 

[Golden Warrior]

I just explained why Reshiram is male xD

Well, most people like it better that way. Some people like having Reshiram be female in their mind. Personally, I don't care about the yin and the yang stuff, I just like imagining that my Zekrom is male and my Reshiram is female.

 

[Myles]

"Those were the main ones. We had previously decided they would be black and white dragons, and that they'd be Fire and Electric type. I wanted to have a pretty stark contrast between the two, so Reshiram was given a light, airy, ladylike design while Zekrom has a much tougher and manly look. The tails on both Pokemon are the central points of their respective designs — they're based off of those electric turbines you see, and they give the impression that they're these great big generators of fire or electric energy." ~Ken Sugimori

:P

 

[The13thSage]

Just throwing out my opinions:

Articuno - Female
Zapdos - Male
Moltres - Female
Mew - Female
Mewtwo - Male
Entei - Male
Raikou - Male
Suicune - Female
Ho-Oh - Male
Lugia - Male
Celebi - Female
Groudon - Male
Kyogre - Male
Rayquaza - Male
Regirock - Male
Regice - Male
Registeel - Male
Latios - Male
Latias - Female
Jirachi - Female
Deoxys - Male
Dialga - Male
Palkia - Male
Giratina - Male
Azelf - Male
Uxie - Male
Mesprit - Female
Darkrai - Male
Cresselia - Female
Manaphy - Male
Phione - Male
Heatran - Male
Regigigas - Male
Shaymin - Female
Arceus - Male
Victini - Male
Reshiram - Female
Zekrom - Male
Kyurem - Male
Cobalion - Male
Terrakion - Male
Virizion - Female
Keldeo - Male
Tornadus - Male
Thundurus - Male
Landorus - Male
Meloetta - Female
Genesect - Male

 

[Gothitelle.]

to add to my list.

Dialga should be a boy and Palkia should be a girl. Boy vs girl rivalry = awesome. Also one is blue and the other is pink :p (also Palkia should be Dialga's older sister lol)

Giratina (origin forme) should still be a girl. She looks more like a girl than a boy. And hey she's cute D:

Giratina's altered forme should be older and more mature than the origin. That said she should be a woman :p. And a female being dominant over the others... is awesome

Arceus... should be a man. He seems more male to me. And he a bigggg deal.

Reshiram and Zekrom should be guys. They seem more like guys. Even Reshi.

Darkrai should be a guy. Ehh looks more male to me.

Shaymin should be a girl. Flowerss and she has pink and she seems girlyy :3

 

[WilfMott]

Male
Zapdos, Moltres, Mewtwo, Raiku, Entei, Ho-Oh, Regirock, Registeel, Latios, Groudon, Rayquaza, Deoxys D+S, Azelf, Dialga, Giratina A, Darkrai, Phione, Heatran, Regigigas, Arceus***, Cobalion, Terrakion, Tornadus, Thundurus, Landorus, Zekrom and Genesect N+S+B+C+D.

Female
Articuno, Suicune, Lugia, Regice, Latias, Kyogre, Deoxys N+A, Mespirit, Uxie, Palkia, Giratina O, Cresselia, Manaphy, Shaymin L+S, Virizion, Keldeo, Reshiram Meloetta and P+A.

Either
Mew, Celebi*, Jirachi*, Victini**

* I'd say it was more female.
** I'd say it was more male.
*** Although I'd love it to be female.