No, no, no - the most interesting BB was Glory, by far. (S.5) We all knew Evil Willow was just a temporary aberration, and the Master was really only a stock, old time vampire. But you never could be sure who Glorificus would be this episode.
But by far the most boring and and uninteresting Buffy character, worthy to stand among the greats, is Riley FInn, from the Initiative. (S4)
He could have been awarded the Teredo Award for it. I mean, just look at him...
And he got even more boring once the Initiative was taken out of the picture.. Id like to have seen a show based around the initiative .