I would say that for me, the top three stories with the best-rounded characters all came out in the same two year period. In order from most to least engaging, I would say:
- The Daredevil "Born Again" Story arc
- Watchmen
- The Dark Knight Returns
I'd be a little surprised if you haven't already read these, but if you like, I would be more than willing to expand on why I hold these in such high esteem.