Sacred 2 was and still is my favorite ARPG of all time, with the ability to go any direction you wanted, follow the main quest or any of the hundreds of side quests that you'd run into. There was no hand holding in that game, or channeling you to the next area. And the Blind Guardian concert quest is still unique in ARPGs.really liked that you got to pick two classes and pick skills from both skill trees to make builds, which I hadn't seen before in an ARPG. However, I couldn't get past how linear the game is after being used to the open world of Sacred.
I really liked Titan Quest, mostly because of it's unique theme, but as you said, it was very linear, and it pales in comparison to Sacred 2. That game should have been way more popular than it was.