The Witch & The Pig’s Twitter: Shouldn’t have to explain that…
DriveThruRPG.com: Where I buy most of my PDFs. Awesome website.
Basic D&D Rules: WotC’s offering of the Basic rules was quite nice of them, now wasn’t it?
Surfarcher’s 5e Monster Analysis: A very in-depth analysis of the math that makes Monsters–and, in reality, Player Characters–go and break things with large weapons.
Stan’s 5e Rules Summary: A DM-screen rules summary, since the DM screen from WotC doesn’t come out for a while.
Stars Without Number: An awesome, OSR-based sandbox sci-fi RPG that I dearly love to write things for.
Eclipse Phase: A transhuman sci-fi horror table-top RPG. Quite fun, if you’re into that sort of thing.
Eclipse Phase: Identity Crisis: Example of Eclipse Phase, and well worth the long read.