TLDR: what's your favorite tabletop system (mechanics only! not about the setting!) and why?
Longer complicated question: I've never played tabletop or pen-and-paper-and-dice RPGs much, so I'm not very familiar with how many there are that are distinctly different from each other, not mostly-clones. I was contemplating that shelf in the bookstore's games section the other day though, thinking I really should do a little research to get myself familiar with the variety of tabletop gaming systems, especially things that are quite different from the old few tabletop systems that RPG video game systems were originally based on. I want to get familiar with innovations in tabletop land in the past 15 years. So, anyone want to recommend a unique system or new development within a system for me to look at?