Too many tasty hot dogs to name, but a few absolute favorites:
Chicago hot dogs with the usual works, nothing held back.
Chili, cheese and onion, or even just chili and onion. Best I've had are at the original Coney Island Nathan's.
Cincinnati-style Coney which is made with the Cincinnati chili-type of, you know, chili.
Sauerkraut, etc. Oh, the list goes on. And I haven't experimented nearly as much as I'd like to.
It's great to have them out somewhere, but I can, and do, make all of the above at home. When ordering them, I take them however they're prepared. At home, I love to put them on the grill and get some char* for even more flavor.
*You can't have Charles without some char.