I'm not part of the Old School Renaissance or whatever OSR is supposed to stand for, but I follow blogs from a few people who are. They've come up with some good stuff. A couple of the best game writers I've found are part of the OSR movement. But there's one major flaw in all their work, even the good stuff - it's all about D&D.
I've certainly got nothing against D&D. It's the first RPG I ever played; it's the lingua franca of most roleplayers; freelance D&D writing bought me a car once. A cheap car that's currently self-destructing, mind you, but a car nonetheless. However, there are more old games than Gary And Dave's Original Brand Dungeons Ampersand Dragons. Some of them are even, dare I say it, better.
When I want to teach someone what an RPG is, or when I've got a large group of mixed ability, or when I want a rules-light game that can handle whatever the players throw at it, I turn to this:
Take your eyes out of the dungeon and look up at the stars, people. The first edition of Star Wars: The Roleplaying Game, lovingly crafted by Greg Costikyan and West End Games, is where it's at. Flexible character creation. Skills that are both minimalist and robust. As much monster and environment craziness as you care to use. And everybody knows the backstory.
Except for this one argumentative 12-year-old I once had in a game, who'd only seen part of the original movie and wasn't impressed. Even she had a good time.
Can we call a game from 1987 "old school"? Yep. It's almost one generation old as humans go; that makes it ancient for an RPG. And it's had a shoddy remake by WOTC, which ought to qualify Star Wars as "old school" in anybody's book. It even has some horrible clunky mechanics that you can easily house-rule without breaking the game. For my money, the very first edition is easily the best one - it has a velocity and looseness that got sucked out of later iterations.
And when I play, the only canonical part of the Star Wars universe is the very first movie. I enjoy new games and new ideas, but sometimes you have to stick with the basics.