Let's eliminate some from that list.
Rast wrote:KEEP
p - a +2,+2 long sword of electrocution (weapon)
N - a +1,+1 battleaxe of chopping
V - a -1,-2 vampiric war axe
Y - a +1,+2 whip of electrocution
KILL
l - a +1,+0 whip of draining
m - a +1,+2 trident of freezing
q - an uncursed whip of venom
s - an uncursed spear of freezing
y - a +3,+2 elven spear of freezing
J - a halberd of venom
T - a -2,-3 eveningstar of draining
I tossed out draining because of the XP loss and because it's just on a whip and you have an electric whip available.
Ditto for the whip of venom; electric whip trumps that.
I tossed out spears because other than throw-ability, the trident is superior.
I kept the vampiric war axe because you can use it and chop with it and you're a deep dwarf and it's an axe. It sucks that it's negative.
I think it will be between the war axe and the electric whip till you find a demon whip.
My two favorite weapons are whips and tridents because you get the whip speed (and train to demon whip) and tridents have reaching and both are usable with shields (and you can train to demon trident).
If I were playing, I'd toss the war axe because it doesn't allow easy swapping and uses up your permafood, but that's me. I'd prefer if you were full health that vampirism gave you a small amount of sustenance on a successful attack. It's the reason I don't use it.