I always figured either bologna was just hot dog meat or hot dogs were just small bolognas. They taste pretty much the same to me.
Actually very similar in texture and in the base recipe and preparation.
The one bologna that I really do like, however, is sweet Lebanon Bologna, preferably Seltzer's. It's a hard core tradition in Central Pennsylvania. Comes in two varieties -- the aforementioned sweet and standard, which has a more sour taste. It's also either smoked or has liquid smoke added.
That said, while it's called bologna, it's not. It' actually a form of sausage closer to salami and is in fact a fermented sausage, with lactobacillus bacteria accounting for the tangy flavor.
Lebanon bologna on rye with Swiss and a good, strong mustard was always one of my favorite sandwiches to take to school when I was a kid.
Ask for it down here in Virginia, however, and they look at you like you're nuts.