"Asked a question that received 50 answers."
You could have a few of these:
Socrates: bronze, 50 answers
Plato: silver, 100 answers
Aristotle: gold, 150 answers
Or, if you're not into the whole ranking-Greek-philosophers thing, you could just have: Inquirer (50) and Philosopher (150)..
Well I'll admit these names aren't so great, except "Philosopher" which I love, so I welcome suggestions. But the concept is solid - questions that many people feel the need to answer are remarkable and as such badge-worthy IMO.
Some examples of questions that have > 150 answers (most of them have much much more):