Umm I had a friend who we play with bring me a bonzai tree once. I thanked her well for it later
. But over all I don't want presents from anyone. I think the only thing I would require is that they bring condoms (sure I have some too but I think it is only polite) and if going to a hotel offering to pay for some of the room. Let's face it we are both getting something out of this so we should both pay for the room, but that's just me.
Otherwise I think just being there is enough. It would seem like they feel they owe us something just for lettimg them play with us and that doesn't seem right. If they want to buy me a drink or something that's okay too (becuase I don't drink very much).