Ooo... Let's see...
Fails that are most likely my fault:
Catalinbread Galileo... built it and anguished over not being able to get it to work... twice. Spent WAY too much time scraping tracks, reflowing solder, and testing components. Was not meant to be and it was probably the build I was most looking forward to. Definitely just my own incompetence.
Big Muff 66 Triangle. Maybe I've got something wrong, but the sound reminds me of Jim Carrey in Dumb and Dumber "You want to hear the most annoying sound in the world? EYYYEYEYYEYEYEEYEY!!!!"
Bigfoot Magnavibe. Tried and tried and tried and all I can get is just a very faint vibe out of it.
Fails that I think I built right, but which turned out shite:
Proco Rat. It whines, it sputters, it went in the bin.
Little Angel Chorus. Fuck a stupid PT2399. I could get it to work right if I periodically stabbed the underside of the vero board with a screwdriver.
I know this sounds negative, but I've built a lot more that sound amazing and made me feel kind of god-like. I'll list some of those in the other post.