Although the route is mostly through France, Quebrantahuesos (205km, 3500m) is Spain's premier cyclosportive. The level of organization, vibe, live tweeting, post-race carbs, free massages, and draft San Miguel, is so well done that the field should take note. A true celebration of Spanish cycling, the Bonebreaker is a must-ride (at least once) for roadies in Spain.
Starting from Sabiñánigo, the grueling route encompasses some of the most demanding mountain passes in The Pyrenees. Participation is by lottery and usually cuts off around 9,000 cyclists from more than 15,000 entrants. I finished in 7 hours 43 minutes (26.5kph), earning a gold diploma for my age group.