That's a tough call. Drinking a Pan Galactic Gargle Blaster is like, well, having your brains smashed out by a slice of lemon, wrapped 'round a large gold brick. On the other hand, the Zany Carter Deluxe is Marc's creation and is reputed to cause people to travel 168 hours into the future.
Having worked with Marc here at MobileRead; I suspect the Pan Galactic Gargle Blaster is safer (ask anyone about those parties at Marc's house). I'll go with the one that's only an alcoholic equivalent to a mugging. Pan Galactic Gargle Blaster for me.