I say the Nurgle
DW is best based on its solid performance. It very reliably smashes faces. The blissgiver is good if there is some heavy
MC/
TWC/other multiwood gribblies in your local meta. Tzeentch I've actually enjoyed using on a term lord in a walking term squad with a RAC and some combiweapons to help out, and it was highly entertaining, and highly expensive. I would keep that for fun games though

. The khorne
DW has bitten me in the

so many times it pains me to use it anymore, but it does have fantastic potential.
And I'm with Kubik, releasing the winged lord/sorcerer from the rhino to tie up another squad such as
dev's/looters/etc can be effective when done in the right time/place