I don't think any of them could top IV for me. San Andreas' story had its moments but the series still had that cartoony vibe which took away from the dramatic potential of what could be a really good story with CJ. IV is when the series took itself seriously. Traumatised Yugoslav Wars vet tries to escape his past, is consumed by his sins while everything he builds is taken from him. Everything you do hurts a wounded antihero you want to succeed while Philip Glass plays over a rainy Gotham.