I remember playing Arcanum, when I was younger, during the Fallout/Baldur's Gate years and I thought it was absolutely amazing! I'm glad that GOG finally put themselves together and released this game :D Oh, and by the way, there's an high resolution patch available to this game, it higly reccomended you try this game out with the high res patch: http://www.terra-arcanum.com/downloads/ and here's a link for a couple of unoficial patches, mostly fixing typo's and other stuff: http://www.gamershell.com/all/arcanum/downloads.html
Anyways, this is a great game, and it comes highly reccomended! :D