Want to know my personal favorite? It's ConferenceBadge [1]. The design is clean and the page is very snappy. But what I absolutely love is how they answer every question that I might have on the landing page itself. I am not personally a fan of Close.io's that sells itself as "close more deals," but doesn't answer how.
I think a landing page should answer what it does, and how it does it in very unambiguous terms. Too bad so many SaaS companies try to make promises without giving an idea on how they'll deliver them.