...uh.... canned spam? The "worst" thing I eat right now is non fibrous fruit (fructose that stays in your system too long is apparently evil). I only cheat on junk food two days out of the month and I really don't crave that stuff anymore. Its more like a two day period of rememberance.
Now if I had to say 'gross', but not necessarily 'unhealthy', there's a lot of things that I can eat by themselves that most people would recoil at. I love that meat water in cans of vienna sausages. I love pickled things, olives, pepperoncinis, etc. Undercooked meat is a situational delight, no blood though.