Mine are all very recent...
My top 5...
1. 2023 v. Michigan- Main reason here would be for Saban to walk off with one final national championship... it would have been the perfect ending.
2. 2010 v. auburn- This game still sticks on my craw. The ides of Mark. The Ingram fumble with the magic bounce down the sideline. Barron's torn pec that limited him in the 2nd half (especially on a key pass play). If Bama wins, not only is it a victory over auburn, but it knocks them out of the BCS title game in favor of TCU. Would have been two wins in one.
3. 2021 v. Georgia- Beating them a 2nd time in about a month, ripping their heart out and eating it, would have been absolutely glorious. Not sure Kirby would have gotten back up off the mat.
4. 2022 @ Tennessee- A win would have meant Saban retried with a clean record against them which would have been incredible (both from a consistency standpoint and a humor standpoint). Also, if all else stays the same, Bama goes to Atlanta instead of LSU. And we know what Saban-led Bama teams did in Atlanta.
5. 2016 v. Clemson- A win that night in Tampa gives Bama/Saban another perfect season, which would have been nice. It was also the last game I got to watch with my Dad before he passed away... wish it had ended with a win and confetti.