I havent had a really bad one, but if those b*st*rds try to sell me stuff i dont want to buy with money i dont have i will kill them all.
I.e. I walked in for a Land Raider.
I left with a Land Raider Terminus, a Land Raider Crusader and i was lucky to avoid getting a 3rd. Oh, and i got a bottle of black spray paint.
Other than that, they are awsome
(If slightly obsessed. Last time i spoke to one about a Dreadnought he pretended he was one and made noises for the Assault Cannon and everything. And made up a story pretending to be Azareth of the Dark Angels threatening to deem an Imperial Commander a heretic unless he gave him a Baneblade. Slightly screwed in the head perhaps, but i admit it was relatively funny at the time
)