After enduring that disgusting final weekend of the 2004 NFL regular season, I came to the conclusion that a new tie-breaker is needed. How a team performs during the final weekend should be the first tie-breaker, with all the current tie-breakers falling in line after that. A team that won its final game would hold the first tie-breaker advantage against a team they're tied with that lost its final game. If they both lost, both won, or both tied their final game, then the current tie-breakers would take effect in the order that they currently exist. That would accomplish at least three of positive things.
First, a team with a one game lead for a playoff spot, headed into the final weekend, would have more difficulty "backing in" to the playoffs the way Minnesota did that year. By all rights, New Orleans should have made the playoffs instead of the Vikings. They finished with identical records. However, the Saints won their final game, while the Vikings lost theirs. In fact, under the NFL's current crazy tie-breaker system, the Vikings' loss, while ultimately not damaging their own playoff hopes, ironically was one of the major factors that kept the Saints out of the playoffs! Under my proposed rule, the Saints would have been in and the Vikings would have been out.
Second, it would keep more playoff berths/positions open going into the final weekend and maintain more excitement and suspense all the way to the end. Currently, a team with a one game lead for a playoff berth, bye, home field advantage, and/or seeding can have that position clinched before the final weekend if they own the tie-breaker over the team(s) they lead. Under my proposal, that would not be possible. That position would still be open through the final weekend of the season. For example, the Pittsburgh Steelers would not have clinched the home field advantage in the AFC in 2004 until they beat Buffalo in the final weekend, instead of having it already clinched going into that game.
Third, it would also keep teams with one game leads from having de-facto "byes" during the final weekend. Take Indianapolis for example. The Colts' game against Denver that weekend was meaningless to them, even though it meant everything to the Broncos. Although the Colts had only a one game lead over San Diego for the number three seed in the AFC, they owned the tie-breaker over the Chargers. I don't care what anyone says, the Colts, with their lack of effort, effectively rolled over and allowed the Broncos to win, which wasn't fair to Jacksonville and Baltimore, the teams competing with the Broncos for the final AFC playoff spot. Under my proposal, the Colts would have had to win to maintain their third seed in the playoffs.