Year One: A look back a year after 4th Edition was released.
Dungeons & DragonsAdventurer's Vault 2
Eberron Player's Guide
Martial Power 2
Player's Handbook Races: Dragonborn
Player's Strategy Guide
AdventuresThe Slaying Stone
Dungeon AdventuresDead by Dawn (level 2, Chaos Scar adventure path)
Heart of the Forbidden Forge (Eberron)
The Crawling Fane (level 3, Chaos Scar adventure path)
Board GamesDescent: Journeys in the Dark
Mansions of Madness
Super Dungeon Explore (Arcade mode)
Card GamesBoss Monster
Dungeon WorldClass Warfare: Mo' like class warfail. Seriously, the price tag, move repetition, low-quality layout, Creative Commons art, and lack of information on how to make moves make this a lackluster, bloated tacklebox of amateur moves. Save your money and just learn to make your own moves: it'll do you better in the long run.
Inverse World: One of the most uninspired, cliche, poorly written, over-hyped, and overpraised third-party works I have ever seen.
Pirate World: Though technically not dead in the water, for backers anyway, this allegedly "explosive" sourcebook is still a dud.
OtherInverse World Accelerated As the Dungeon World version above, but with even less content (despite the same price!).
Numenera Eeeh...maybe the next billion years will have some interesting stuff going on.