A new theme that seems to be making the rounds on some popular forums is the theory of the "Nerd Crush Unit." The idea behind it is that everyone has that one unit, or model that you love to field. No Matter how bad or good it might be, you always find a way to put it in your lists because dammit, it's just so damn awesome...in your mind.
Maybe its due to your bad ass paint job on it, or maybe its because it was the first thing you purchased, or maybe it's because it has won you so many games...we all have that one unit.
Mine currently is the Slaanesh Daemon Prince in the new Daemon Codex, with Fateweaver coming in a close 2nd.
Yes he's expensive, but he's worth it.
I give mine 3 Mastery Levels, a Greater Reward for the Lash of Despair, Daemonic Flight, Warp-Forged Armor, and Maybe and Exalted depending on the rest of my list.
What makes him so amazing, in my opinion, is the fact that I can basically change him from game to game.
With the options available to daemons before the game, I can adjust him on the fly to what ever I need.
-Need Anti-Air? Check. Biomancy.
Iron + Lash = Amazing.
-Opponent have a lot of shooting? Check.
Telepathy. Invisibility + Puppet Master = Game Changing.
-Need Anti-Mech? Check. Biomancy.
Iron Arm + Endurance = Invincible.
-Playing against Hordes? Check.
Excess Powers can decimate hordes quickly.
-Happen to have an Exalted Reward in a kill point game and no need for the Portaglyph?
Eternal Blade + Iron Arm!
He is the ultimate Jack of all Trades in my opinion, and for that reason he will always been in my Daemon lists...unless its Rogue Trader.