4. Tiger Woods and Elin Nordegren - 2004
Estimated Cost: $1.5 million
These two tied the knot in a top-secret ceremony in Barbados, where the golfer rented out the entire Sandy Lane Resort for their 120 guests. The reception featured a performance by Hootie and the Blowfish and a fancy fireworks show to boot. It's worth noting that their divorce cost the athlete over $750 million after his cheating scandal.