Not sure about the greatest comeback ever. What about these truly amazing games?
1987 - Denver vs. Browns. 98 yard drive w/5:38 seconds denver ties and goes on to win in overtime with a field goal.
1993 - Houston vs. Bills. Houston has 28-3 lead at half time. Down by 32, the Bills score 7 touchdowns. Houston ties with a field goal with the Bills win in OT with a field goal.
1980 - Saints vs 49ers. Saints up 35 to 7 at halftime. SF scores 14 in 3rd and 14 in 4th to tie then win in OT with a field goal.
I watched the first two games on this list as well as the game last night and personally I don't think there is much in common other than they played football. This game was much more reminiscent of the very fortunate outcomes the bears enjoyed the one season under Dick Juron.
Of course, last nights game might compare favorably to the Saints game...
If anything the Bears (offence, defense and special teams) should send a thank-you card to the Cardinals for living up to their reputation for their ability to lose any game.
{No, I'm not a native Chicagoan and I didn't drink the cool-aid in 85 either; although the pre-game comparisons between Erlacker:Singletary, Grossman:McMahon and Smith

itka were hilarious in the context of the game that was played}