Squid guts!
 

Served gratis by a sushi chef in Milwaukee. To this day, I'm still not sure if I should be honored or if he was playing a nasty trick on me.

Vile, vile stuff.............

Had durian (ok, can get good Durian ice cream in Thailand), horse (good in Verona), dog (good in Vietnam), bulls testicles, etc. Culturally odd to this American but quite tasty. Same with insects, scorpion out of the vodka bottle, etc. Perhaps more effort to eat than warranted, but not disgusting to the tongue.

Kumis on the otherhand was the only thing I've had that induced mild nausea and a strong laxative effect immediately - a reasonably common reaction for those who've never had it apparently. It's a mildly alocholic central asian beverage made from fermented mare's milk - most any market will have a woman with a large barrel full of it and bowls to serve it to you for $.25 or so. The texture is gritty and gloppy, the taste is sour, the experience is memorable.

I was at a small izakaya in Tokyo. I had a couple courses already - sushi, some fried items, etc. The chef/owner was impressed and said he'd never seen a white person use chopsticks so expertly (I think this is mostly testimony to the very few gaijin who came in there, not any special ability on my part). So he suggested I try a winter time delicacy - cod fish sperm sacs. I didn't know what it was when I ate it, because of our language barrier, and had to figure it out once I got back home. It was tasty though!

I've cooked and eaten pizzle and testicles (bull and sheep), and even served them at parties. Tasty. Fried grasshoppers and various larvae were crispy and salty. I like fresh durian but only if it has had the white pith removed. I like horse meat, sea urchins, pink kidneys and fried brains. I've eaten a wide variety of tasty meats from wild porcupine (you could still see the quill holes on the skin) to farmed kangaroo and crocodile. I have had, and enjoyed, everything from pajata (veal intestine that still contains the mother's milk, making them creamy) to bone marrow to congealed chicken blood (nicely spiced in a noodle soup).

I really didn't enjoy the barbecued field mouse (aka rat) from the roadside stand in Thailand. Maybe I needed more Thai whiskey to wash it down. I don't understand why dried sea slugs are a Chinese delicacy. I can confirm that eating cheese that moves is more about bravura than taste.

I wish that the fried spider vendor at the market in Cambodia hadn't sold out before I had a chance to get a bag to try.

I like to try the local cuisine wherever I travel. In Peru and Bolivia I had alpaca, llama, and cuy. The only weird thing about the cuy is that I saw the live ones running around in a cage (and they looked so cute) near the roasted ones on a skewer.

Swallow soup in Bangkok (Chinatown).

Grasscutter in Ghana (bush rat) - a delicacy there
Fugu in Kobe (poisonous blowfish)...a great experience

Most of mine are common:

Ostrich - Texture of Beef, milder flavor
Horse - A bit tough, somewhat gamey flavor
Haggis - Similar to a strong unseasoned sausage/wurst
Escargot - Not that uncommon. Didn't care for the texture
Venison - Have had farm raised and non...The non farm raised was quite gamey
Tripe - I've had menudo (made with tripe) The smell and taste remind me of being in a meat market in Mexico City (not a positive one)

Something I don't think I could ever get the nerve to try is Casu Marzu (Sardinian Pecorino cheese infested with insect larvae)
http://en.wikipedia.org/wiki/Casu_marzu

A few regional delights from my trips to Mongolia:

... also known as airag in the Mongolian language. If you find that the drink is too gastrically disruptive, you can enjoy the flavor without the side effects by indulging in aruul, which is a hard sun-cured cheese made from the coagulates of fermented milk.

I have also enjoyed bodok, which is barbecued marmot. Tasty and fascinating to watch its preparation.

Interestingly enough, in Mongolia regular beer is known as shar airag, which translates as the "yellow" version of fermented mare's milk.

turtle soup.

I have to say I love raw horse meat (as a Tartare).
Otherwise, Bear (not bad actually), durian, bird's nest, sea urchin, crocodile, ostrich etc etc.

If it is slightly whitish and gelatine like, its not swallow soup. Its swallow spit soup

Had the same experience at the big seafood market in Seoul. The octopus was really quite nice. Cold and fresh tasting right out of the tank, drizzled with sesame oil, hot sauce to dip. Was a bit chewy, though. The little pieces tend to die down after 4 or 5 minutes.

Donkey and Potato Stew
Duck Gizzard Salad
Some of those raw cheeses in France that smell like gym socks
Octopus

a mixture of grounded up bone, fat, gristle and god knows what, slapped between 2 buns.

I believe they call it a hamburger