The most popular emulators that people use are Null DC Bear and Flycast.
This is because of the 3 non-digital console releases of the game, the Dreamcast one is the closest to arcade feeling. The most popular ones are Dreamcast based emulators. There are many different emulators that you could use to play Marvel vs Capcom 2. Emulators such as Null DC Bear and Flycast have always been the most popular ways to play Marvel vs Capcom 2, but now they have rollback netcode and a ratio select mode. While these emulators have had online play integrated in, recently these emulators have gotten an upgrade.
The most popular way to play Marvel vs Capcom 2 is through emulation. In light of the recent #FREEMVC2 movement, Marvel vs Capcom 2 has seen a huge resurgence in popularity. Marvel vs Capcom 2’s community continues to push the game to new heights with the addition of rollback netcode and a brand new ratio mode!