Do or don't: Surprise parties

My darlings, I have a question: Have you ever had (or thrown) a surprise party? My mom's 60th birthday is next year, and I'm trying to figure out whether we should throw a surprise party or tell her the fun plans ahead of time. Personally, I wonder if surprises are overrated; I like having months of giddy anticipation before an event, and I think walking into an unexpected party might feel surreal. But am I nuts? Would it be totally amazing? I would LOVE to hear your thoughts!
P.S. My mom is on vacation right now so she won't read this post! :)
(Top photo by Sharon Montrose; bottom photo unknown)