i agree with the usefullness being a big part.
but personally i am into graphics, therefore i regard burp as one of the top projects. One day when you can submit your own renders it will be useful to me.

Whereas with predictor and many others i dont recall much being found so far. (the number projects are the exceptions as primes are found fairly frequently but again on a "real" level if these are discovered or not they make no difference to me).