I almost never join in on these, but what the hey. Seeing so many other cool lists made me wonder if I could even pick 15 games, as I tend to be more of a "reader who games" than a straight up gamer. But, to my suprise more than 15 immediately sprang to mind, though some required a little research to find the actual name of games that I remember as "that space mining game" or "that all magic users game". Anyway, here they be, in no particular order save number 1.
1. AD&D 1E - most played game ever both for me and probably 95% of gamers I know.
2. D&D B/X - you never forget your first time.
3. MERP - I played the hell out of this game, and miss it.
4. Twilight 2000 - from back when we still expected the bombs to fall any day.
5. Squad Leader - what I immediately think of when I think of "war game".
6. War & Peace - the biggest and best wargame I ever played. It takes like 3 months to play, so I only ever played it twice.
7. Risk - what can I say?
8. Microlite20 - Everyone should have about 15 copies of this stashed in their various campaign setting boxes or books for instantaneous gaming.
9. The Lords of UnderEarth - my favorite fantasy microgame.
10. Revolt on Antares - my favorite scifi microgame.
11. Star Frontiers - probably number 1 on my "I should really break that out and play it again" list.
12. Wizards Quest - my favorite Avalon Hill fantasy game, I played with 4 friends quite recently after tracking down a copy on ebay and was pleasantly surprised to find the game just as good as I remembered.
13. HARN - number one on my "wish I had had a chance to play that" list. I've spent a lot of time drooling over the maps nonetheless.
14. Diablo - possibly sacrilege to include a computer game on this list, but its, in my opinion, the best dungeon crawl you can get on a flatscreen.
15. Stratego - cause my junior Ravyns love to play it with me!