what i can only think of right now....perhaps not an all time top ten.
comp top ten-ish:
*VGA Planets (first lan game i've played)
*Archon (apple ][e, wizard chess my a**, Harry Potter can go KY himself)
*Seth Able's LoRD (first BBS door game i've played)
*TekWars? (2nd BBS door game i've played)
*AO
*Civ series
*King's Bounty (precursor to Heroes of M&M, beats HM&M by a mile)
*Sim series (exception for SimAnts which i haven't played and SimEarth/Life which is way too drab)
*Marathon series (Mac FPS. one of best engine's i've ever seen)
*Descent series (best space FPS. WC can't compare)
others up there
*Star Control series
*Elite
*Rainbow 6: RS/CO/UO/BT
*Syndicate
*Cossacks
*Art of War/Art of War at Sea
*Shadowgate
*Zork (first text-based offline game i've played)
console/arcade games tops:
*Super Mario Bros. 3 - Famicom (nothing can top this)
*Metroid - Famicom (wicked atmosphere, great gameplay)
*Salamander - Famicom (Konami offshoot to Gradius, best shooter)
*Faxanadu - Famicom (first action-rpg ever, think castlevania with buying/selling gear + xp)
*Kingdom of Ys1&2 - PC Engine (almost able to kick FF's ass)
*SD Gundam: Capsule War - Famicom (best board war game, best SSI's Panzer General 2 by a mile, PG2 is definitely 2nd best )
*Beatmania IIDX series - Arcade/PS2 (best music + cool videos + simple&addictive gameplay)
*Virtual-On Oratorio Tangram - Arcade (best robotic sim fighting game)
*Virtual Fighter 4 - Arcade/PS2 (best 3D fight sim)
*Guilty Gear XX - Arcade (best 2D fight sim)
*Marble Madness - Arcade (first+most addictive game played with a trackball)
err...that's a lot more than 10....=P i guess that's all for now. different genres definitely cannot be put together for an all-encompassing top ten.