What I think will be canon

1 Yes Man
2 NCR
3 House
4 Legion

What I hope will be canon

1 Yes Man
2 Legion
3 NCR
4 House

IMO yes Man has some interesting lines just before the real ending. Lines that beg for DLC or a sequel, however DLC would be nearly impossible with multiple endings. Caesar turns New Vegas into his Rome, but that could be done elsewhere as well. The game seems to be somewhat set up for the NCR, but I doubt the devs would throw away any opening for a sequel.

I want to see something with the reformed Khans. I like the diplomatic strategy with them in NV. I feel like it would be fun to chill with Jack and Diane around the campfire.

and sing the campfire song song.

Get the Lonesome Drifter and some Party-Time Mentats and you've got a shindig on your hands.

Multiple endings and you can have multiple so-called canons, no ending being the correct ending, canon really being the unique style content of a game anyway, as in Fallouts 1,2,3, series. Fallout4 will follow that canon, and so on.

Variations on the series, as in Fallout Tactics, New Vegas, can be more loosely cannoned off the series, as they were.

Variations and scenarios are limitless, different yet still be in keeping with that unique style content canon that is 'Fallout'. The imagination of game developers such as Bethesda will ensure that the Fallout 'horse' will never flag.

The story can go on anywhere in keeping with that canon.

well it depends what the game designer make cannon. like in fable they chose good to be cannon and so far thats been the truth in the fallout series. so I figurr its staying ture
so my vote is yes man
he was the most good choice you could get

Eh House was better I think.

I think that the canon ending will be either Mr. House, or the Yes Man ending. I think that most players took those routes.