The most underrated Broncos Raiders game occured in 1973 on the final Sunday of the NFL season. Most Broncos fanatics don't even remember that we played Oakland straight up for the AFC West crown on the final Sunday of the 1973 season.
Oakland entered that game with an 8-4-1 record while Denver entered with a 7-4-2 record. One of Denver ties was the famous "Orange Monday" game that Meck references above. That was the first great game in Broncos history.
Anyway, the Raiders beat the Broncos 21-17 on that final Sunday in '73 to steal the title from us. Most people like to hype the 77 team as the first good team in Broncos history, but there was another Division Champion caliber team, that lost the division title by merely 4 pts. The 1973 team.