I can understand why people choose GB2 (the courtroom scene for me will be the greatest and the outbreak scene too) but for me, 1984 has me in a chokehold with its quotes, charm and humour. The second one does have its moments, don't get me wrong, but I feel like 1984 has this perfect blend of comedy which both kids and adults can enjoy, supernatural horror and wit.
For me though, GB2's ending kind of ruins it. It just didn't feel much like a fight. I don't know. It was a bit underwhelming in that respect but I do love the movie anyway because it's Ghostbusters and it's nice seeing the gang together. But if I had to choose between the two, 1984 all the way. Actually, for me, having rewatched all of them, if I had to rank them...
1984 > Afterlife > Frozen Empire > GB2 > 2016