It seems that the term "ultimate" is actually a moving target. What is the ultimate bow today may not be quite so ultimate tomorrow. That's what makes threads like this fun, because you see so many points of view.
For me it is the Howard Hill bows. They are the classic American Longbow design, they have a history of being associated with one of the greatest archers ever, and are just plain fun and very effective.When traditional archery is mentioned, a HH bow comes to my mind.
There may be many bows that are technilogically more advanced, but thay just don't have the romantic (literary usage of the word romantic) appeal of a Hill bow.
But as Rob S. stated there is no single ultimate bow. It is a matter of personal preference. Wouldn't it be fun, though, if we could all get together for a big shoot and have everybody bring his/her personal ultimate bow? There would be some rousing debate around that campfire for sure.