You are trying to compare some very different films. Delta 100 and HP5+, for example, have ISO ratings two stops apart, and have very different grain technology. What do you mean by 'best'? Why would you want to push Delta 100, when you could use Delta 400?(posted 9133 days ago)Having said that, it is my experience that the T-grain films (like Delta) do not respond as well to pushing as the traditional films (like HP5+).