Do all Passiflora bear fruit? My neighbor had one they never got fruit on and some don't mention the fruit when you are looking at the vines.
If they all do bear fruit what are the best?
This is not a straightforward question to answer. Literally, yes, all Passiflora species, and indeed most natural flowering plants must bear fruit in order to sexually propagate. However, many species require a separate clone of the same species in order to create fruit. Hybrids are a completely different issue, as many are sterile. There are even some that will create fruit from foreign pollen, but will always be empty. As for which fruit taste the best, that is a matter of opinion, which is extremely varied, but P. edulis is the most commonly grown for eating.
I hope this helps!