I choose love. A career can be important, but I've lived on the streets and still known happiness . . . and hunger, but that's besides the point. ;)
Love is amazing. It makes life more vivid and colorful. At the end of a 50 year career, you have a retirement home. At the end of a 50 year relationship, you have a lifetime of smiles and laughter.
Honestly, it's possible to have both. It's not easy and sometimes it just doesn't happen, but if you can get both, I say shoot for it. Also, if you can have a career you love as well as a person, then all the better. :)