Maybe this is more suited for the Role Playing board, but seemed to fit here.
So what's everyone's favorite table top RPG game and why? This can be a specific edition if you like. I'm not doing this as a poll since there's so many of them, plus trying to get all the editions would be too many options. It can be because you loved the setting or even the mechanics.
For me, I've always loved the Storyteller games Vampire: The Masquerade and Mage: The Ascension. When I first got into Vampire, my mind was blown. Prior to that, my only experience was AD&D 2nd (not 2.5) and some of the earlier 1st Ed books I obtained. The mechanics were so much more clear than D&D and it was all character and role play focused, rather than kill count. The worlds were dark and mysterious with conspiracies everywhere. All the unique clans were extremely interesting. Besides, hanging out with the Goths in highschool made this game all the cooler. The Interview With The Vampire movie had come out right before I got into it, so made it extra cool, where Vampires weren't just bad guy monsters but tragic characters in their own right.
For mage, it was because it was such a unique take on magic, where paradigm and belief mattered a lot. It's definitely one of the most unique systems around with all the magick Spheres being nothing but vague descriptions that you can mix and match together to create effects. It did require the player to take those effects and work them into their characters paradigm and come up with how their character would actually accomplish that. Do you use incantations and draw symbols on the ground? Do you pray to Jesus? Do you build a plasma rifle? Throw bone dust into the air to raise the level of chaos in the area? The system allowed everything from the more traditional Hermetic, Pagan and Shamanistic magics to weird science and VR and cybernetics. It created a crazy world, but was so fantastic in how much uniqueness and diversity it encompassed. Literally every possible thing could be right in that game, it had such a wonderful ambiguity to it.
Outside of those, I absolutely loved the Dark Sun setting for D&D. It turned all the standard fantasy tropes inside out and upside down. You had 7 foot tall Elves that were short lived but could run for days on end at top speed, half dwarves that could labor for days, crazy bug people (Thri-Kreen) and cannabalistic Halflings in the few jungles that remained and everyone had psionic abilities, even the animals. It was also the postapocalyptic D&D setting, where the world was ruined through the use of magic destroying the environment. It was a truly unique place in the realm of Dungeons and Dragons. One problem was the metaplot from the novels kinda ruined it with fixing the problems with the world that made it so interesting. I think I heard with the 4th Ed reboot (ya 4th ed, ugh) that they had rolled back those changes. Hopefully they decide to do something again with the setting. Magic was pretty much outlawed, except for the Sorcer Kings that ruled over the few remaining large cities and the people in their employ.