I started off playing the precursor to the Avernum games, Exile. Each Exile gameworld was *huge* and I used to play it for so long I started seeing the graphics in my dreams. While I do have some quibbles with update/remake of Avernum (less party members, can't equip two weapons, isometric perspective means navigation isn't as simple), the fact is, I can spend ages immersed in these games, searching out the best weapons, mapping out as much terrain as possible, and indeed reading the text. (Hell, I even found myself trying to tidy up the various homes I was breaking into, or dropping of things like plates, pots and pillows in the homes of the poor or by refugees.) If you're not into reading text, this game probably isn't for you, but for those of us who enjoy reading, (or don't mind it if they want a rich, immersive experience) then do try the Avernum series. The graphics may be old and simple but the story and imagination more than compensates.
I first saw this the year it came out at a friend's house. The curtains were drawn, the sound turned up and the game opened. The opening credits came up.... "O.M.G! This is great!" Then we played for a bit. "I love this game." When I got back home, I begun my campaign to get my parents to buy me a copy. Cutting edge graphics and video for it's day that still holds up well, gorgeous music (that has you cursing that there isn't a soundtrack available), and a thoroughly engrossing story. More than worth GOG's low price for such a wonderful game.