Gamasutra recently asked it's readers:
role playing game over the entire history of the genre do you think has made
the biggest 'quantum leap,' and why?"
After a few
honorable mentions, they display the top five. Deus Ex and Planescape are in
there, but number 1 goes to Fallout.
this rpg really has everything a great rpg needs: incredibly robust player
character development, not just combat skills; great original story and
setting, not just another rpg with elves and orcs; a great turn based combat
system for people who like to think, but yet has some of the most rewarding
critical death animations that rival any game, not just rpgs; a rich world full
of interesting npc characters, enemies and places; functional UI, and great
character dialogue system; because the game was open ended and the character
development was really deep, it is actually replayable more than 3 times.
You can read
the whole thing here.
Thanks to Killzig for the tip.