In my opinion, I would drop the US Open, the BCS Championship and the Boston Marathon and replace it with the NBA Finals, the MLB All-Star Game, and the Rose Bowl.

Yeah, those are reasonable nominees. In fact, the version of the list I composed in my head last night the NBA Finals were on the list, and I debated whether to include the Rose Bowl instead of the more generic BCS Championship. I went with the BCS Championship because of what the BCS says about American college football, and what the endless griping about it says about American fans. As for the NBA Finals, I'm not fully convinced that anyone really cares all that much about them.

I guess there are a few ways to look at the question. When you ask, "What are considered the most life-changing events to attend", I think that iconic events like The Masters and Kentucky Derby go way up as does the Rose Bowl. If you look at biggest TV/Radio audience, I think the NBA Finals beats out the Indy 500, the Boston Marathon and Tennis. If you talk about the events that generate the biggest buzz on sports TV and Radio, my picks are:

Super Bowl
World Series
BCS Championship
NCAA Division I Men's Basketball Tournament
NFL Playoffs
NBA Playoffs
The Masters
NFL Draft
Stanley Cup
Daytona 500

Scotties Tournament of Hearts!

I'm not seeing bowling on that list.