An annoying part about wanting to break away from D&D is that all the "experimental" games etc. Get away with having fewer rules. I want another system that can be as complex as D&D but with different focuses.

Forged in the dark is a good example of something close to what I like. What it lacks in combat/interaction diversity it definitely makes up for with the gamified secret base you can customize and the various "down time" interactions you can have.

My DnD 3.5e group is trying out GURPS and it's pretty fun so far.