May 29'th 1995 - my uncle brings me a SEGA Mega Drive 2 for my 3-rd birthday, i start shooting people on Demolition Man [http://en.wikipedia.org/wiki/Demolition_Man_%28video_game%29], over the next 8 or so years i enmass a decent cartridge collection.
1999 - My mom gets a Pentium II for work. I stick to my SEGA.
2001 - A classmate gives me a 1.44 floppy with about a hundred different small arcade games. SkiFree teaches me valuable lessons about life. I start regularing PC clubs with friends.
2002-2003? - I see a abandonware article in a PC gaming magazine. Over modem internet i gain access to games runable on the Pentium 2. My PC gaming horizons broaden and move away from Diablo 2 and CS. Dune 1 and 2, X-Com, Ultima Underworld, KGB, Chaos Overlords, good times, good times.
2005 - My mom gets a new work computer - 512MB RAM, GeForce MX440 - back on the Half Life and CS train, GTA 3, AvP, 3d goodness and whatnot, still 90% don't match the quality of the abandonware i played earler.
2007 - my own PC. GeForce8600GT, 2GB RAM and a 2.1 Ghz Dual Core CPU.
And a few upgrades later, we're in present day. All in all - i'd list Dune 1 and Ultima Underworld - The Stygian Abyss as the games with most influence on me. Effin masterpieces.