I've been thinking about which of the many RPG that I've played or read have been the most important to my gaming. Of course these may have been hugely different for other people. In the end I've boiled it down to these few:
Dungeons & Dragons
The granddaddy of them all, the first commercially published RPG. Personally I started in 1977 a little bit before the real boom in D&D in the early '80s. My introduction to the game was with the Original Game in the White Box with the three booklets of Men and Magic, Monsters & Treasure and Wilderness Adventures. Initially we didn't have the polyhedral dice so everything including to-hit rolls and saves were done using D6. For combat that will have had an impact as the probability curves will have been very different for a number of dice than a single D20.
I started initially playing with my older brother GMing, at first it was just me as a player with a number of characters at once including Theo the elf, Acquila the fighter and Eskel the Cleric. We soon started playing with some of my brother's school friends and I get very hazy now on characters partly as many were very short lived.
Funnily enough despite being a miniatures gamer before I played D&D, using Airfix and Matchbox 20mm and 54mm plastic figures to play games I never really used minis with D&D that much until 3e.
When I came back to RPGing in 2003 after a number of years of very infrequent RP gaming, with that little I did being Call of Cthulhu, I restarted with D&D, but this time 3e. This was at GenCon Europe in Easter 2003 playing throught the Wizard's Amulet and Crucible of Freya from Necromancer Games. From there I've been playing D&D pretty regularly going over to 3.5 to run a campaign in the Wilderlands of High Fantasy and playing in a campaign in another GM's homebrewed setting.
The Acaeum is a really useful resource for finding out about the many D&D products over the years and also useful to see what a book on ebay might be worth.
I'll talk about the other games in subsequent posts