i've traveled around the world and i'd have to say that japan has the best candy for me personally
royce chocolate is god tier in terms of chocolates, although chocolates are probably my weakspot in terms of sweets
https://www.royce.com/contents/english_rcw/
edit: hey i just looked it up and they actually have a small handful of locations in the US
http://order.royceconfectusa.com/pages/royce-store-locations
their chocolate quite literally melts in your mouth, which is something that i have only nearly experienced in some places around europe
i also like pickled plums (umeboshi), and umeboshi hard candy/gum is fantastic, although giving it out at events/lans a lot of people from NA can't handle how sweet or sour it is, although the ones that do actually like it a lot
http://www.amazon.com/Japanese-Plum-Candy-Koume-2-39oz/dp/B003VDX8CU
i've given out something called paicro as gifts, which are basically intensely sweet croissant-shaped chips that taste like butter biscuits mixed with other flavors, and a lot of people really enjoyed it no matter where they lived
http://i.imgur.com/dqEkqtM.jpg
rice crackers and mochi/dango are also really great tbh, and i really enjoy garigari popsicles on hot days which are basically just soda-flavored popsicles
http://i.imgur.com/haABJZX.jpg