The greatest game, ever.
It has an epic, well developed plot, amazing dialogue, many memorable characters, almost unparalleled humour. From the torutured soul of Irenicus, to the enigmatic Yoshimo, the vulnerable Aerie and the hilarious Minsk and Jan Jansen. All the characters intereact well with each other and it has the best written romances of any game ever. This is the main attraction of the game, and no other games does it as well as BG2.
The combat is tactical, with many options, playing out like a minature version of Medieval 2 Total War. This is the second best part of the game.
The graphics still hold up well nearly 10 years after release, with beautiful spell effects and well drawn weapons and lanscapes. The monsters are animated nicely.
The music is beautiful, coming in at the right times. The sound effects send a chill down your spine and make you feel the world you are playing in is real.
Overall, this is the most perfect game ever made. Its a masterful music album, artwork, videogame and novel, all into one beautiful package. Its the only perfect thing in the world today, and I can't wait for Bioware's next game, Dragon Age.