What do you like?
I like books, reading (and related literary tags like writing, poetry and so on), philosophy, classicalmusic, and technology (and related tags of interest, like privacy and linux).
I suppose a nice quirky tag I follow is #birds tag. It's got only two posts, but I'm sure with time it'll change (I might post something in that sometime soon; Perhaps something related to owls...). Another quirky, but really dead and underused tag is #sakamotosunday, which is apparently devoted to posting the music of composer Ryuichi Sakamoto, but there has only been one post in that (I guess I'm gonna fix that tomorrow.)
I suppose those unused tags don't count as good, but I liked them enough to follow them.
Additionally, the main draw of hubski is in reality not the tags, but the people. The concept in my mind is that a person you know posts good quality stuff is more likely to... post good quality stuff. So you follow them and never get something low quality. A tag and the people using the tags might grow to a point where only silly stuff gets visibility, but a good person is not likely to change their habits.
In reality I follow more tags than people anyway, but I suppose if Hubski ever grows big enough, following people might be a better idea.