katakis: I like Sacred, I like Diablo. Spent many hours on both, but both are rather different in game mechanics. Diablo focuses on random generation, monster slaughter and distinct character builds. Sacred promotes quests (by giving unique rewards), exploration; character builds can be more versatile here, because skill scrolls are plentiful and stat growth is automatic.
Quoted for truth.
If you liked the Diablo series you will probably like Sacred, but there's no guarantee as your tastes may not be the same as mine ans Katakis' tastes.
I can't really say much else besides what's been quoted here. Sacred is a different experience and better imho than D2. Graphically, quest-wise, loot-wise. Etc.