In 1994, Jeff Lurie bought the Philadelphia Eagles for $185 million. Today, the franchise is valued at $1.1 billion and is #7 Forbes annual valuation of NFL franchises. So if you've got the cash an NFL team seems like a pretty good investment.
The Eagles were leapfrogged on the list by the Jets & Giants, who just opened their brand new stadium in North Jersey. If you look at the list, building a brand new stadium that you own pretty much guarantees you a spot at the top of the valuation.