I haven't seen them all...but personally, I'm partial to World War Z and I Am Legend. But my favorite has to be 12 Monkeys. Just sci-fi enough. Just real enough. Just trippy enough. And Brad Pitt showing finger.
Re-watching Contagion now. Haven't seen it since it first came out. Their will most definitely be a COVID-19 movie in a few years.
While you're home - The 58 Best Pandemic Movies to Binge in Quarantine https://www.vulture.com/2020/03/best-pandemic-movies-on-netflix-hulu-prime-and-more.html
12 Monkeys Contagion Train to Busan *REC & *REC2 28 Days Later The Stand Andromeda Strain 28 Whatever Later The Crazies Omega Man Outbreak is a horrible movie not sure if zombie movies count eta: The Bay is highly underrated.
https://www.vulture.com/2020/03/12-monkeys-why-terry-gilliams-movie-is-so-relevant-today.html 12 Monkeys Is the Apocalypse Movie We Need Right Now
There is a movie called Carriers with Chris Pine on Netflix. It's not the greatest movie ever, but the story is about people trying to survive the back end of an end of world pandemic - a better fit for current fears than a zombie movie if you are looking for a relevant movie.
28 Days Later is the undisputed champ of this thread and on that fact there can be no debate. Those are the rules.