The original Baldur's Gate is one of my favourite games, second only to its successor and is a game any rpg fan must play. Due to its art style for a game that came out in 1998 it still holds up well today. Graphically this game still looks beautiful due to 2d painting-esque backdrops and thirdperson isometric viewpoint.
The gameplay also has an incredible amount of depth to it and the combat is very tactical and varied depending on the class you play and the party setup you choose. The game is also from an era when games were unforgiving and actually provided the player with a challenge. The combat is similar to Dragon Age: Origins where it can be free-flowing and action oriented but it is highly recommended that players take it slowly and utilise pausing to setup properly between rounds during combat.
The game being built upon the ruleset of Advanced Dungeons and Dragons has a lot of depth to classes and the classes will all playout and feel very different which offers a lot of replayability ontop of just choosing and adhering to different alignments.
Also due to the game being built upon AD&D and being set in a D&D realm the game has an incredible amount of history and backstory in there that the world feels real and is incredibly dark and gritty which ties in great with the dark tones of the main story.
Without spoiling too much of the story it starts with very humble beginning and quickly thrusts the player into a world descending into turmoil with bandits and bad guys wanting to kill you at every turn you must uncover the sinister plot that is unfolding and discover your own dark heritage in the process.
I would wholeheartedly recommend this game although I will warn that there is a lot of reading involved and that the combat is designed to played slowly (unlike diablo and games of its ilk) and very tactically but for those that love a game with a great story this game is undoubtedly one you should play.