That would probably be Adam Wolfe, closely followed by a bunch of Artifex Mundi ones:

1. Abyss (The Wratihs of Eden), with its Bioshock-like aesthetics;
2. The Enigmatis series (especially the 2nd one), maybe because it was the first HOG series I played;
3. Grim Legends 3, which has a bit more diversity than the usual HOG formula.

Cheers!