Right now I'm currently enjoying doing vampire enchanters of Dithmengos, Hepliaklqana, and Oka.
VpEn don't really need any of the benefits of Sif or Vehumet, which leaves them free to focus on other gods. Oka was an accidental choice with one of those altars that give a random god and some extra piety, but it was a surprisingly good choice once the armor gifts started rolling in. Getting boots of the assassin from Oka allowed me to switch from short blades to long while still getting my stabbing bonuses, but also getting long blades' ripostes. It was a good run til it wasn't.
Dith is an obvious choice for the extra stealthy stabby goodtimes, and shadow mimic lets your hexes get a second shot sometimes.
http://crawl.chaosforge.org/Hepliaklqana is an interesting new god that let's you have a permanent respawning follower that evolves into one of 3 types: knight, battlemage, or hexer. OFC, the best complement to a hexer is another hexer for stab city.
I used to consider hexes the weakest magic school, but in the hands of a vampire, it's pretty great. Discord is an amazing spell for later game.