Alcatraz has been on my list to see for years. I used to get to SF about 3x a year for work, but never built in any 'free time' for myself. My boys were all little, needed to get out and back as quick as possible. I finally decided to stay an extra night, just so I could get out to Alcatraz. It rained sideways all day so I never had a chance to get out of the hotel.
Soon after that I took a new job and I haven't made it back since.