For comparison's sake I figured I'd contribute the offensive ranks for winners. I'm just checking the league standings from pro-football reference for total offensive points and for 1966-1969 I'm including the AFL.
#1
71 Cowboys
72 Dolphins (also #1 defense)
79 Steelers
89 49ers
91 Redskins
94 49ers
96 Packers (also #1 defense)
97 Broncos
99 Rams
09 Saints
#2
77 Cowboys
84 49ers
85 Bears
92 Cowboys
93 Cowboys
98 Broncos
06 Colts (tied with the Super Bowl losing Bears lol*)
#3
68 Jets
78 Steelers
83 Raiders
95 Cowboys
#4
69 Chiefs
76 Raiders
87 Redskins (tied with the Super Bowl losing Broncos)
04 Patriots
#5
66 Packers
73 Dolphins
75 Steelers
#6
70 Colts
74 Steelers
01 Patriots
#7
80 Raiders
81 49ers
88 49ers
#8
86 Giants
#9
05 Steelers
#10
10 Packers
#12
82 Redskins (Interestingly, they had the #1 offense the next year, and lost)
03 Patriots
#13
67 Packers
#14
00 Ravens
07 Giants
#15
90 Giants
#18
02 Buccaneers
#20
08 Steelers (this is why I don't rate Roethlisberger, "does just enough to win" for the Steelers is "does just enough to not suck, or suck if you want it really doesn't matter your defense will carry you")
Not surprisingly, six of the eight teams that finished outside the top 10 in scoring offense had the #1 defense. The two exceptions were the 67 Packers with the #3 defense and the 07 Giants with the #17 defense and they sure as hell didn't play like the #17 defense against arguably the most dangerous offense ever assembled.
So Super Bowl champions are well represented among the top offenses in the league, but not as well represented as defenses have been. 17 Super Bowl winners have had either the #1 or #2 offense compared to 24 #1 or #2 defenses. Almost half, or 8 of those 17, occured in the 90s alone. Yet, the very next decade there were 5 outside the top 10. So given what Zombie has dug up I'd say that defense has been clearly more important in every decade except the 90s.
*Devin Hester had 2 kickoff and 3 punt returns for touchdowns and the defense had 1 pick six and 2 fumble returns for touchdowns. That's 56 points or 13% of their offense (56/427). Never mind the 44 turnovers they forced in total. Without it they would have been tied for 8th with the Jaguars. You know I could never give the Bears credit.
Born and bred a cheesehead