Yersinia pestis. Such a lovely name, sound like a beautiful sort of tree or flowering shrub ("Yes, my yard is hedged with Yersinia Pestis -- isn't it lovely this Spring?". Variola major sounds like someone in charge of the variolas in a band, perhaps like a pipe major. Mycobacterium leprae sounds like something that changes grape juice into a truly great wine.

And Tabin and Sarin sound like artificial sweeteners.