I could probably do everything with a OCD or Rockett Archer Icon.
KHDK Ghoulscreamer would be my choice because of versatility in the Tube Screamer family. VFE Standout for least color and focused control.
I guess it's really what you want to do. Tighten the bass. Punch the midrange. Increase gain. Change the attack. In most cases I find I can do these things with just the amp.