Not sure about #2 - 5, but #1 was the 1952 Tech - Alabama game, won by Tech 7 - 3. This November game was the decisive game in our national championship season. I think it may have been the first nationally televised college football game. As I recall, the decisive series came in the second half (I think late 3Q), Alabama leading 3 - 0, first and goal on the Tech 5 yard line. If Alabama scored, it seemed unlikely Tech would be able to overcome a 10 - 0 lead. Tech stopped 'em three times. On 4th down from about the Tech 2, Alabama's Bobby Marlow (over 200 lbs, a big halfback in those days) ran wide. One Tech player between him and the goal line, little 155 lb Jackie Rudolph. Rudolph flipped him upside down at about the 3. Knocked Jackie out, but Tech went on to win 7 - 3. A picture of this tackle was all over the papers. And years later when I was a student at Tech and entered Dean Griffin's office (dean of students) for the first time, this amazing picture covered the entire wall behind his desk.
The $125,000 Tackle (November 15, 1952)
Georgia Tech 7, No. 12 Alabama 3. In the most exciting game, at that time, in Tech annals, Jackie Rudolph's "$125,000 tackle" of Bobby Marlow helped preserve the victory, earned Tech a Sugar Bowl bid (and the $125,000 payout) but also preserved the Jackets' 12-0 season and the Institute's third national title.