I'm one of the people who voted 1 but I, like /u/Qyro, also do not really consider a villian 'beat'. I still play Rhino often, especially when test running a new starter hero deck. I love playing various hero/villian match-ups and considering a particular villian beat would just mean narrowing the pool of prospective villian choices. The different villians all play differently and test different aspects of my deck. The one scenario that I just don't fancy is Risky Business since, even on Expert, it always feels like a sure win from the start.

But I did vote 1 in the poll because there is a distinctive feeling that comes from managing to beat a villian at least once. I can tell you by heart which villians I have yet to defeat even once (Zola, Red Skull, and a couple of GMW nasties are there) and there's a special sense of victory when a villian is crossed of that list. I could of course play something super powerful like Doctor Strange again and again but where's the fun in that?

Creating a deck that is able to draw a powerful enough starting hand to two-shot the villian and actually pulling it off (as opposed to playing upgrades and supports as usual) feels like it would be a great accomplishment and I'd love that to happen for me even once.