I've been using 1Password for almost two years -- during that time, it has been useful on a daily basis and constantly reliable. It integrates well with all the major browsers I use, and keeps data in a format that I could easily migrate if I ever moved to an unsupported platform. The company is constantly working to add features (which are generally free for existing users), they update regularly, they keep up with platform changes (in OS X, in iPhone versions, etc.) and their level of service is excellent. Really a first class experience.