All Pokemon have equal chances of breeding (barring Pokemon of an undiscovered egg group Pokemon) meaning that all Pokemon can equivalently make an egg. Although there is no Pokemon that breeds easier then the other, there are ways of breeding faster:
- Breeding 2 Pokemon from a foreign country
- Breeding 2 Pokemon from the same egg group
- Breeding 2 Pokemon when holding the lucky charm in your bag (Black/White 2 exclusively)
Hope this was of any aid