There aren't too many things I don't like... I worked in Manhattan for a number of years; first time when I was 16. A lot of my earlier experience was built around food. On top of managing a "gourmet" cookie store, I was also a manager in a restaurant in mid-town manhattan. At that time, my wife worked for NYC tourism. We both had many opportunities to go to all kinds of restaurants, some of the best in the city, and some pretty cool gala events. With all that, I was exposed to every kind of food imaginable.
French, Italian, Greek, Carribian, Puerto Rican, Chinese, Russian, Mexican, Cajun (hotter than hades) Spanish, Japanese (I would eat sushi / sashimi every night if I could afford it

)Thai, Indian, Mid-Eastern and even Ethiopian, (you eat wih your fingers, no forks

). There's probably more that I can't recall.
Fois Gras? (it's cooked not raw) is actually very good (although it's not good for the goose). They actually force feed a goose so that it's liver enlarges and gets fattier.
Caviar? I've had some of the most expensive (never bought any

) and while it's admittedly an aquired taste, there were some that were very good,
Head cheese? OK, I'll agree with you on that one

Not exactly my favorite but I would try it again.
Liver? Oh man! There is NOTHING like the smell of liver and onions cooking. If it wasn't for the fact it's so high in cholesterol, I'd eat it more often.
Limberger? There are worse smelling cheeses than that but, oddly enough, very tasty
Squash? My mom used to make squash (that my old man grew in his small garden in Brooklyn). It was actually squash and eggs and italian cheese. Put that on a big ol' piece of fresh itallian bread and you've got a meal.
Veggies? I have to admit, there's one thing that I just do not like and that's beets. Although I liked borsht which is Russian beet soup.
Here's a list of just some of the strangest things I've eaten

Most of which were quite good and I've had more than once. Get ready to hurl
Sweetbreads (that's the thymus gland of a calf)
Tripe (that's made from 3 of a cow's 4 stomachs)
Raw Squid. It tastes basically the way you'd think it would taste and is very chewy

Raw shrimp. On the same plane as raw squid. Much better cooked.
Various other types of raw fish that happen to be totally NOTwhat you would expect, very delicious and "unfishy" tasting.
Miso soup (Japanese tofu, seaweed and scallion soup)
Snails (French escargot). Lots of garlic.
Pigs knuckles and pigs feet
Chicken feet. Yep, not much to them, but more than chicken lips

Cactus
Rocky mountain oysters (not good for the bull)

Kangaroo meat and other strange game meats... I'll take good cut of beef any day over them.
I'm sure there's more... My motto is "give it a shot" and you may be pleasantly surprised how something you thought would be aweful is actually quite good.