Drox Operative is nice game, that can keep you busy for many hours. Is a hack n slash rpg (diablo-clone) with many unique elements, and a lovely feeling that you can shape the diplomacy of each area as a "neutral force" between AI's controled factions (ofc after few hours you will learn the tricks). I do not know for the rest of the games, Din's Curse has a good reputation as diablo-clone with rogue-like elements and random events.