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.
Wayfarers. But I am biased, because I wrote it.
I am still working through a final rewrite.
Here's a review of the Player's Manual.
The structuring of the game takes those risky, exciting early levels of a characters in OSR games and manages to expand that into high level play. By making healing less accessible, increasing damage, and reducing hit point growth, characters will find combat a risky proposition, but the game provides numerous ways for characters to interact with the world to bring about more subtle means of negotiating a challenge than simple combat.
PM me if you want some comp PDFs.