Maybe I'm old, but I immediately thought of Billy Hatcher...
Kent's shot bumped Hatcher to #2 IMO because it won the game and established a new high-water mark for Astros postseasons. Hatcher's shot more dramatic though to me for several reasons -
1. Like the Ausmus whack, it came from a very unlikely source (Hatcher was a renowned slappy and had only hit 6 HR all year before the AB);
2. Unlike the Kent situation, the Astros were at death's door (very stressful top of the 14th with Senor Smoke, lucky Mets only scored one run) and all the life was out of the building with one out before Hatcher steps in;
3. Early in the AB, Hatcher hits one a mile down the LF line, but about 20 feet foul. This roused the crowd, but there was disappointment in that he probably missed his best opportunity as nobody's expecting a tying HR from this guy, just hoping for him to get on as Davis is due to bat 4th in the inning. Amazingly he gets the same pitch and doesn't pull it quite as much.
4. Like Kent's, this was a moon shot (Loge level) and part of the ensuing pandemonium was the shock over what a mammoth shot it was.
5. The ball hugged the line, and nobody knew if it was going to stay fair.