I think that though the Bears could have won that game (maybe 2 or 3 in 10 chance) the Colts were just better, so I can live with it. The Hester return of the opening kickoff was an electric moment and even though they lost I still remember that season fondly.
My top 3 bitter losses:
1) NFC championship against Packers (the Cutler/Haney game). Obviously because it was against the Packers and led to their SB win. The Packers were hot but I think the Bears could have won that game at home - probably about a coin flip - had Cutler not gone down. I understand the injury was legit. Haney gave it all he had and almost tied it at the end.
2) Flutie vs the Redskins. Seeing the SB champs squander a lead and not get a chance against the Giants hurt. FU Charles Martin.
3) Cody Parkey. Of course this one still stings but I doubt they would have gotten past the Saints and Rams, and they are still young and improving. And they had other chances to win that game.
Most bitter regular season loss may have been game 1 against the Packers this year, but that was not bad in the end based on how the rest of both teams’ seasons played out. Edit to add: On second thought this one cost the Bears a playoff bye and led to them having to play the Eagles in the Parkey game. So actually I’m still bitter.