Michael, my little brother, says that Star Wars is more popular than any other type of media in the world, including Touhou.
Science Time! BV
First, as a technicality, Star Wars is not a type of media. It is a franchise spanning around a movie series that has been brought to pretty much any relevant medium. Thus we should compare different franchises to one another.
Second, the question is on what grounds popularity can be measured, evaluated and compared.
The most obvious idea would be to judge by the size of the fanbase. This would, however, bring up the eternal question of what constitutes an actual "fan".
If we set the bar low, then Star Wars would easily win out against touhou because it is generally a widely known movie series throughout the world, whereas touhou is well known only in Japan. However, in that case, there are many other well-known and popular franchises or artists who can rival Star Wars's. How about Star Trek? The Beatles? Disney? Harry Potter is on it's way there.
If we set the bar for "true" fandom high, then even with Starwars's expanded universe, the merchandise and all other ascpects, Touhou should not be too far behind, if at all, and several other franchises should be there as well. Star Trek says "hello" again, for example.
Middle ground is difficult.
If you want to include everybody who knows of the work and then quantify singular fans by degree of fan-hood, then I will tell you that this is futile on enough levels that I shouldn't have to explain it.
If we go by the size of works the franchise has produced, even with Star Wars's huge amount of merchandise, the Expanded Universe novels, the games et cetera, this all is not enough to overcome the ridiculous amounts of fanwork generated by the Touhou fandom.
:munch:
Oh, and on the topic of my own stance on Star Wars, yeah, the movies were entertaining. Even episode 1 and 2, because I hadn't seen the originals and was too young at that time to anticipate what was supposedly wrong with them. Then again, I don't regard the original trilogy as the huge masterworks many people claim them to be.
Oh yeah, and this thread may be better suited for the general off-topic forum, but don't take my word for this.