Did Buffy really love Angel more than anyone/anything?

In her argument with Xander about slaying Anya, Buffy said that she killed Angel even though she loved him more than anyone and that she would have given up everything for him.

Do you think that's true??

Personally, I was shocked when she said that because I didn't think they even dated for that long for her to put him above her friends and family, but what do you think?