I backed some miniatures which came though, the first pebble and then the Time2 that got canceled when they were bought out by fitbit. I got 100% of my money back and I love my pebble time but the battery won't last forever and now I'm screwed on smart watches. I don't really want anything beyond telling time and showing me notifications, the iwatch and all the Android watches do way too much.
I also backed the Ouya, man, that was a mistake. I have put 5 bucks in a few projects just because I believed in them but didn't have the money right then to back enough to get the thing.
I'm lucky though, the only failure I backed that fell through I got my money back.
EDIT: Oh yeah, and the Pandora and Pyra. Just as I wrote this I realized it is 'what your you backing, not backed. Oops.