Mind Flayers: Minsc or (insert favorite tank here) and brine solution.
Flayer slaying is then like beating up on goblins. If no brine solution
is available, try stealth, speed and surprise. Dead Mind Flayers can't
hit you with psionic blast.
Vampires: Daystar undead-nuke. Backstabbing with flame-tounge is also nice.
My stalker took out that spellcasting-vampire minion of Bhodi (forgot
her name) that way. Her contingency spells went off post-mortem.
Liches: The good old Summoning/pierce magic/breach/false dawn/chess game.
Or see above.
Dragons: LOTS OF RELOADS

. Has anyone hit the shadow dragon w/ daystar?
I missed daystar with my first group and the others have not met the
shadow dragon yet. I will try it, but if it works I will reload.
My Cavalier would not stand for such a dishonorable act. He prefers to
be level drained.

Demi-liches: MORE RELOADS. What do you mean that Viconia's magic resistance
does not affect imprisonment??? Every round at will? Hey, where did
everyone go? 100% magic resistance? Why don't my lower resistances
work? Then try Minsc w/+4 weapon or Korgan w/+4 weapon.
Beholders: Aside from SoB and the Cloak, try fire elementals. I cleared the
(certain ch2/3/6 quest) beholders that way. Works like a charm.
------------------
- Cayle