I wouldn't say I have a favorite persay, but when the population gets under 90 I like to seek out the oldest living male and the youngest breedable females, then turn him into a master breeder. Just keep him going into that hut over and over with the ladies.

I noticed that the older villagers tend to have twins and triplets more then the young ones. Since the ladies who are "elderly" have the chance of dying before the two years are up and the babies seem to just vanish into the ether when that happens instead of being adopted - it's better to use the eldest male then an elderly female. If he dies it doesn't affect the females or the babies.