Share 'What do you grow but get bad results?'

A take off of Sharon's recent question and something I'm curious about. For me it's carrots and peas. I keep planting them and they keep sucking. Peas do OK, but space limitations seem to keep me from growing enough for a meal. Not to mention, all my instructions say that they don't need a trellis but then why the hell won't they stand up on their own? Carrots are my worse thing though. Most of…