I came across a link the other day that read My Ten and he found it here. In it the blogger poised a question what RPG books would you keep if you only able to keep 10 of them. You have to own the books for them to be on the list. So without further ADO here is my Ten
Dresden Files Your Story, I am huge Dresden Files fan and the book is written in the voice of Billy the Werewolf which makes it feel like I am reading a Dresden book. On top of that Dresden Files uses the FATE system which introduces a lot of new thoughts on RPG design.
Pathfinder Core Rule Book, I tried 4e, I tried Savage Worlds, but nothing feel like home to me except 3.5 and Pathfinder fixed all the glaring issues and improved it. Pathfinder is a must.
Pathfinder Bestiary, pretty much because the Pathfinder Core Rule book does not have a Bestiary.
Marvel Heroic Roleplaying, new to the market but making a splash. Marvel uses the Cortex Plus system and as with Dresden introduces a lot of new concepts in RPG design.
Star Wars: SAGA Edition, I won’t say the best Star Wars RPG, but it is the easiest to pick up and run.
D20 Future, this book has a whole lot of info for different versions of Sci-Fi games one of the only RPG books I like to pick up and read over and over again.
Wheel of Time RPG, when ran right this game rocks and has a great magic system.
Alternity: Stardrive, I sort of inherited this book. But I have read it over and every once in a while return to it. I like how it maps out human progress and shows how humanity got to the stars.
Dragon Age RPG Box Set 1, based on the Dragon Age video game, this system is Rules Lite but you can do so much with it. It reminds me of 3.5 but stripped down and throws in Talents.
Monte Cooke’s World of Darkness, interesting book and a cool modern game I also love the fluid magic system.
Traveller Core Rulebook, I don’t own this book but I am really interested in the game.
I am sure not everyone will agree with my list but I hope it will give you thought on your list.