Once again, i get beaten to the punch by my little brother (Grrr)!
Had a conversation with my mate Dan at work earlier about 'beardy (or sometimes cheese-factor 5) lists' and if they're appropriate in our games of Warhammer 40,000. My view is that if they're created, themed and played in the spirit of the army then they're fine. When they're math-hammered and maxed out to the point of becoming un-beatable, that's when it spoils the fun.
Example 1 is this: Vulkan, 10 Thunder Hammer Terminators, 3 Tactical Squads with Melta/Flamer combinations and drop pods, 3 Speeders with Melta/Flamer combos.
I think that this is built in the spirit of the list and is totally the point of Vulkans abilities, improving the effectiveness of the Hammers, Meltas and Flamers. In play it will be devastating against some forces and not touch others.
Example 2 is something like: 2 Daemon Princes with the Lash, Wings and whatever else (that old chestnut...), Beserkers and so on.
The background of Chaos is that Slaanesh and Khorne don't go for coffee that often, so combos like this, for me at least, aren't in the spirit of the 40k story. That being said, they're still codex-legal...
Pete of Team Gambit