Please, if you are going to try any video game - try and play for a while - Planescape: Torment. It is considered by many to be one of the greatest computer role playing games ever hula’d. Based on the 2nd edition AD&D rules, it the game can be played many different ways, based on the class you follow, the skills you assign, and your alignment - your overall attitude on life - is generated on the fly as you respond to situations.
There are quests, skills, nice graphics, etc, but the real thing is the story. It’s excellently told, if you find it original or not. Would make a good book, kind of along the lines as Memento meets I don’t know what. Romance, combat, humor, Shena Easton playing a fiendling, succubi, a grim and determined hero, floating skulls, an eternal war, a man trying to redeem himself - if you want him to…
Otherwise, if you don’t like this, play:
Sanitarium - if you like adventures - fantastic, strange, but very cohesive in its own way
Arcanum - an RPG - Dwarves with rifles, Orcs in tophats - D&D meets 1860
Wizardry 8 - a natch - you liked Wizardry - a helluva good game
I’ll second System Shock 2 - I’ve played SS1 to death and really loved SS2 - but it can be very difficult depending how you play. I hear they ripped this game off to make Doom 3 - sounds right. Very ingenious use of sounds, etc.
Fallout 1 & 2 - you HAVE to play these if you like RPGs
Unreal Tournament 2004 - kill, kill, KILL!!! Fun, but if you want to relax - I find it impossible to play this and relax - fun - yes - relaxing - no - I only play in onslaught mode, myself. Me kill with tank 
Neverwinter Nights Platinum - very nice graphics, some fun stories, so 3.0 D&D, awesome, multiplayer
I loved Dark Age of Camelot - but the problem with most all MMORPG’s is that it takes too much time - I only have an hour here and an hour there - not any more 
Good luck!