Taric Vayne is meh because his CC doesn't reposition. Cow Vayne used to be the best but support Cow sucks now so it's probably Vayne Blitz.
Leona/Vayne is still the best if you ask me. Sure, it takes some very careful coordination, but the burst you can pull off is just incredible. I've seen people bursted from 80% to dead from properly-coordinated kill setups.
Alistar or Blitz can do the same thing without coordination beyond "Hey I CC'd the carry, you have 3 seconds to follow up and CC them again so that they're CC'd for 5 seconds for free."