All of them :P I ship everything. But the Regina ones most seriously.

She's my favorite so I ship her with a lot of people; David, Billy, Peter and August.

I ship her with Hook & Graham. & I kinda liked her with Neal.
As for the others, I ship Hook only with Emma. Regina with Robin, Red with Whale & Belle with Jefferson

Please ONLY vote if you multi-ship the character with at least 7 other people!

Graham ,Neal & August (somewhat ; prefer them as friends) also with Regina but only as non-canon ,I like some of her scenes with Hook too .

@LLheart...I don't think I multi-ship ANY character (from anything) with 7 or more characters.
You asked which we multi-ship the most...nothing about how high the number is for our multi-shipping.

I ship Emma with Hook, Regina, and Jefferson.

Actually I now have three for Regina, as well. Tink, Emma, and Robin.

Regina and Emma the most!
Regina: Emma, Robin, Rumpel, Tink, Hook, Graham, Jefferson, Daniel (wow 8 o_O I'm pretty crazy... and that's not even including objects xD)
Emma: Regina, August, Hook, Neal, Graham, Jefferson and Gold

^ Thank you @Diamond_Queen! Now that is what I am talking about! ;-)

I myself have a character from this list that I multi-ship with at least 10 persons (!) Yeah that's right 10! I am not kidding & objects are not even included 'cause that would be way too weird! :P LoL Anyways I guess I should have rephrased the question better @Rumbellefan11

and hook

@LLheart, haha you're welcome, I do love shipping!;)

I mutli-ship Rumple the most ^^

^Lol I multi-ship Rumpel so much as well xD But since he wasn't in the list I didn't consider him... haha

NEAL + Jefferson + Graham + August