So yeah, what the title asks. What's your favorite tabletop game, roleplaying game system and why should others play it?
For me, it's Marvel Superheroes. Though you can probably blame that on my GM. To me, MSH requires a good GM because of how story-driven it is. You can spend a whole session never rolling dice or you can spend the whole session rolling. So, if you like story-driven and/or games requiring lots of creativity, I highly suggest Marvel Superheroes.