You know what I want to see? And what would make a hell of a hybrid? Klingon/Vulcan mix. Is it even POSSIBLE? (Doubt it!)
It's happened. Remember Ba'el
from TNG: "Birthright"? She was a Klingon/Romulan hybrid, and Romulans are Vulcan by species. (EDIT: Oops, just beaten to it.)
Non-canonically, in the novels written by William Shatner with Judith & Garfield Reeves-Stevens, Kirk falls in love with Teilani, a member of a genetically engineered Klingon-Romulan hybrid race.