I did STP last year and I'm not sure I would do it again. It is a lot of people and most of it isn't to spectacular. My favorite part was riding through Seattle at sunrise with thousands of other bikes. The novelty of the crowd wore off pretty quickly though. I did it as the 'rite of passage' others have talked about. Check!
I live up in the Northwest corner of the state in Bellingham and will concur that we have a lot of nice roads around here. I haven't done RSVP but it looks like it hits some good spots. And bellingham is a good place to drink a couple beers after a day of riding
. I guess between the two, I'd vote for RSVP
I'm learning about a bunch of rides here, that Chelan century looks like fun.
Forrest