what legendary pokemon is least common in the games?

[Forsythiel IV]

So i was thinking today and it came to mind that some legendary Pokemon are less common then other legendarily. Just want to find what you thing is the least common legendary that you come across people having and what is the most common.  

[BogiePop]

I'm going to guess manaphy or shaymin, any event only pokemon really.  

[Hex Sableye]

Least common i would have to say is mew or jirachi. Most common id have to say is any in game legend. Especially mewtwo.  

[TwilitOni]

I'd say Meloetta and Genesect, as both have only been released once each so far(in the U.S. at least).

 

[starkaat]

Hoopa and Volcanion :B
...Pretty much agree with what everyone else has listed. It definitely used to be Celebi, back when there had never been a US release.

Most encountered are probably the box legends from whichever gen? Mewtwo, Arceus, Deoxys, and Latios also seem pretty common.