I looked this up today after I had another division-winner lose in the semis, found the results rather interesting:
17 1st-Place teams - 3 titles
6 Wild Card teams - 4 titles
8 1st-place teams, 90+ wins - 1 title
9 1st-place teams, <90 wins - 2 titles
1 Wild Card team, 90+ wins - 1 title
5 Wild Card teams, <90 wins - 3 titles
2 titles from 10 90+ win teams (one didn't make playoffs)
5 titles from 14 playoff teams with <90 wins.
Anyone else care to share their playoff experiences? :)