I ship Buffy with Riley even though I'll always love her best with Spike. I ship Willow with Oz, even though I believe Tara is her true love. With Rory, I really can't decide if I like her best with Jess or Logan. Ryan and Lindsay were cute, even he and Marissa belong together. I have my favorites, but I like other couples too :)

for me it kind of depends on the couple involved.

I do sometimes, it really depends on their chemistry and relationship. I never HATE a couple just because I prefer to see one or both of the characters with someone else, like a lot of people seem too.

Usually no.

For some yeah.

I ship Chair, Nair AND SereNate on GG so that's definitely multishipping.

I love Brulian and I don't mind Lincas
I also don't Mind Booth and Cam on Bones god I am dead now for saying that
But I don't want Flack to be with anyone else apart from Angell although now she's dead he has to find someone else

I'm more of a Bangel,but I really love Spuffy too.
I love Addison with Mark,Alex,Derek and Pete.
I love Dair and Darena.
I ship both Willow/Tara and Willow/Oz.
I ship Xordelia and Xanya.
.................

Sometime it depides on the couple

It depends ;) For example:
I love Xander with Cordy and Anya (Anya more), Angel with Darla and Cordy (Darla more), Lois with Oliver and Clark and Mark with Addison and Lexie (Addie more), but I can't imagine Bones with anyone but Booth and Chuck with anyone but Blair. And I only love Buffy with Spike, but I adore Spike with Dru, so I guess it depends on a character.

There is only character on TV that I love with two people and that is Leroy Jethro Gibbs ;) I love with him with both Shannon and Jenny :)