This is one of the first rpgs I ever played, and I still love it to bits. The graphics (especially with the fan made resolution patch that allows you to set the resolution to whatever you want) and music combine to produce an incredibly atmospheric and unique experience, quests are numerous and complicated (no simple courier/fetch/kill quests here) as well as original, and character customization is great (wimpy characters with silver tongues are loads of fun and often capable of avoiding combat). NPC companions are memorable, and your decisions affect their opinions of you (to the point that they will leave or be unwilling to join your party) and what quests you can do and the overall ending of the game.
Voice acting is excellent but scarce.
The map is large and the game long. The first town is perhaps my least favorite and can involve some extremely frustrating combat depending on your stats and whether you're trying to play a character with saintly morals, but don't let it put you off. Combat grows less frustrating as the game progresses.
There is a large modding community associated with this game that I recommend checking out. It has created at least one very large content addon and several mods meant to balance out the game (in vanilla Arcanum technologists and especially gunmen are at a disadvantage to mages).
Anyway, this game is fabulous. Buy it. Now.