1) Blades in the Dark. It fits the kinds of stories I like to tell/play, of coworkers who don't have to like each other but are stuck in a high stress job, and what they're willing to give up to get that done.
2) Fate. It's a generic enough system that it's pretty easy to expand to tell a pretty wide range of setting or story, even if it does need weird dice.
3) D&D. I'm not happy about this choice, but it'll hit the widest number of players, so I'm likely to get to keep gaming.

Savage Worlds, because it is endlessly versatile, lightweight, and easy to teach.

Traveler, because space opera.

Pathfinder, because it's close enough to D&D that I can pull people over from the dark side of Hasbro without too much setting whiplash.

Runequest, because Glorantha is awesome and it's an endless source of stories, even if i'm not so fan of the BRPG.
A generic pulpy system, maybe Savage Worlds, maybe another one, something that can be tweaked according to my needs and whims.
The One Ring, because Middle Earth is one of my first loves and it's the game that catches the best the mood of this world.
And tons of paper and pencils because designing systems is a big part of the fun.