Good: most food you get from burger vans. Seriously, they sell easily the most unhealthy, greasy burgers, sausages and kebabs but they're delicious and keep you full for half the day with a decent portion.
Bad: deep fried gum balls. Went to a fairground once, and they were selling these. "What could possibly go wrong!?" I naively thought. It tasted like burning hot, sickly sweet glue which refused to shift from my mouth no matter how much I choked and spluttered and gagged. Alarm bells went off when when it blocked my trachea, and someone called an ambulance, I still have a scar from the tracheotomy they painfully performed on me. And on top of that, it took a dentist an hour to remove the gunge from my mouth and throat.
Wouldn't recommend.
Oh, and the guy who was selling them got fired. Yay, I guess.