10.Dungeon Crawl Classics
The newest addition to my list, and if I'm not mistaken, the most recently published of all these books. The cover to DCC just makes me want to play the damn thing. It also gets the music to Shadowgate stuck in my head. Something about the lone adventurer facing down the unknown... very cool.
9.In Nomine (Original paperback version)
I remember seeing this in a game store called The Danger Room in Columbia, Missouri. I was captivated by it. It's pretty minimal, and I found myself instantly drawn to the book. I love how much the cover could capture my interest and imagination without much of anything on it at all. I found the subsequent version of cover for this game to be fairly hideous.
8.Blue Planet (1st Edition)
This, like In Nomine, captured my imagination. I love the vivid blue. This cover gives me the urge to explore the unknown. I remember seeing this book at the first convention I ever attended, Conjuration, back in July of 1998. The cover alone was enough to get me to buy it.
7. Wraith: the Oblivion (1st edition)
The cover of the first edition of Wraith featured a glow in the dark title. My wife bought a beat up copy of this edition, which is worn in such a way that you can barely see the title on the cover unless you turn out the lights. This makes her copy extra awesome. I specify 1st edition because the 2nd edition of the game was a hardback book with no glowing letters, and thus it was lame.
<---Our copy is not nearly in as good a condition as this pic.
6. Big Eyes, Small Mouth (2nd Edition)
5. RIFTS Conversion Book I
The awesomeness inherent in this cover needs no explanation.
4. Ninjas & Superspies
If you need me to tell you why I think this cover is awesome, I have nothing to say to you. Ever.
3. Shadowrun (1st/2nd Editions)
I really love this picture. I love the ragtag look of the Shadowrunners, who look more like they just left a Joan Jett concert than a Neo/Morpheus look-a-like contest. I like that the cover features decking, magic, and gun play...it just manages to encapsulate everything that is Shadowrun in one picture. Hell, they thought it was so good, they didn't even change it out until 3rd edition, when the characters were really starting to look dated. I have found all subsequent editions to have lukewarm covers by comparison.
2. OpenQuest (Revised)
I bought OpenQuest because of this cover. I admit it. There is something about the color scheme, the murky yet lush look of the forest, the classic dungeon entrance, the rugged adventurers...this cover just sparks my imagination. I was a little weirded out by the pipe-smoking anthropomorphic duck that appears to be part of the adventuring party, but later I discovered that ducks are a mainstay of Runequest, from which this game is derived. I can appreciate the shout out to the game's source material.
1. AD&D 1st Edition Dungeon Master's Guide (later printings)
The green-robed wizard (who, in my childhood, I thought was "the Dungeon Master" flinging open the door to gods-know-what...this book captured my imagination at an early age and hasn't let go. To me, this illustration is D&D. This illustration is the very essence of what gaming is to me.
I'm happy to say that I still own most of these books. I am unfortunately missing my copy of Blue Planet and have been for years...I bought it in high school, carried it around my senior year, and then... not sure what happened to it. I actually forgot it even existed until a year or two ago. I may well have lost it in one of the seventeen frickin' times I moved during/after college. I got rid of BESM 2nd edition during an unfortunate "I'm too grown up to like certain things" phase (that I have since gotten over), but I don't have a strong desire to replace it.
...oh, and I guess my Shadowrun book is 2nd edition, not 1st, but it's the same cover.