Yup, finally jumped on the bandwagon. Here's what I use in my campaign. Most of what I've owned has been lost along the way (big pile of Dragon magazines, old campaign notes, a bunch of books and heaps of board games) but life goes on. These days I use a modified version of the Pathfinder BB rules (does anyone use RAW?). 4th Edition has never been played but I thought it had I whole bunch of good ideas in it, not least chucking out the whole Great Wheel cosmology and introducing something a bit more usable.
Runequest was the first roleplaying game I ever bought. This isn't that copy but one I bought from The Games Room in Elm Hill, Norwich. The finest shop in all the multiverse if I do say so myself. I've been shopping there since I was eleven years old (I'm now 42!) and always pop in when I'm in town. Next to that is the famous red and blue books and the Book of Marvelous Magic followed by 1st Edition and some modules. I really like 2nd edition stuff. The fluff is really good but the rules were starting to creak even then.
Top shelf of non-D&D stuff. Paranoia is still one of my favourite ever games. Love Mutants and Masterminds too. Old Warhammer stuff is great for setting detail and ideas, I really like the grittiness of it. Merp is in there as well. Iron Crown produced the most beautiful role playing setting s ever made and I'd love to get hold of more of their stuff.
3rd Edition stuff and Greyhawk bits. Still love Greyhawk after all these years. My map is now getting quite tatty but maybe if I ask Santa nicely... The Forgotten Realms book was quite pricey when it came out but it really was worth it. You can see the writers weren't just bashing it out like they were in the mid-nineties. City State of the Invincible Overlord was bought purely for nostalgia. Great fun but totally bonkers. Lankmar, City of Adventure gets used more, it's just more to my taste.
There's my junk, hope you enjoyed the tour!