Anime_Foxx
Personally, one of the more unusual things I have eaten is Rose flavored soft cream (ice cream) and azuki bean (sweet red bean) soft cream. The Rose one was... weird. It wasn't bad but I don't think that it would be my top choice next time I go to Japan. I did really like the azuki bean one, I would definitely recommend it.
BTW if anyone takes a trip to Japan you'll notice that they have a lot of different ice cream flavors that you can't get anywhere else.
Wasabi: Do not try! Apparently ice cream and spicy just don't go together
Rose: Nice to try just to say that you've tried it but I think it tastes like perfume blech!
Azuki: very good
Apple: This one's also very good. It's got a sour kick to it like green apple.
Chocolate Banana: Another very good one but not exactly unusual I'm afraid.
Green Tea: again, good flavour
There also a lot of other ones that were unusual and flavours that you wouldn't be able to get anywhere else but I didn't get to try them