Personally I don't like Phoebe and Jason together, it was way to boring for me. There was no action or "Spark" between them. And just for the record, since everyone is talking about Cole and Pheobes relationship I'm gonna add my two Cents in on their little relationship...
I liked Cole in the first couple seasons he was in, He made a good demon. But when they started dragging him on and on about Phoebes love I just think he became the Demonic Stalker from hell (Literally)