Used to be kosher dogs from Katz' supermarket in Rockville, MD. We'd boil up a bunch of them during the Redskins games and wash them down with National Premium. I put mine on a plain bagel and heaped on Katz' cole slaw and that was it. Hebrew National dogs were also pretty good as was their knockwurst.
Nowadays it's Morningstar Farms Veggie Dogs on a whole wheat bun. They taste kind of neutral so you need various combinations of diced Vidalia onions and Vidalia onion relish, Gulden's Spicy Brown, kraut and picalily.