In terms of stag activities, you can do whatever you want on a Hamburg stag do. Paintball the stag into the middle of next week, party in a designer suite, learn to wakeboard. And don't forget to spend an evening checking out the summer beach bars, which pop up along the banks of the Elbe when the city council imports sand for the warm months!
When night falls, the coolest city in Germany really comes into its own. Hit the Reeperbahn (red light district) for an authentically seedy evening's fun, or head to the water to see home-grown rock and electronic acts bring the party to enthusiastic crowds. The Beatles played here when they were still small, and Hamburg has never forgotten its contribution to music history.