Microsoft cofounder Paul Allen. Tom Pennington / Getty Images With an estimated net worth of $17 billion, Microsoft cofounder Paul Allen can afford to buy himself some fancy toys.

But with interests that range from electric guitars to World War II aircraft, Allen takes expensive hobbies to a whole new level.

He also happens to own the Seattle Seahawks, who will be playing for their second consecutive Super Bowl win this weekend.

We've rounded up some of the billionaire's most ridiculous toys, from professional sports teams to submarines.