It has to be steak and kidney for me, in a good gravy and decent steak. Shortcrust pastry too, none of that disintegrating puff stuff . . . a good pile of chips and gravy, maybe a mushroom or two.
I also prefer the whole pie not a slice of a bigger one - it's not the same, and I feel that someone else could be getting more filling than me, so it has to be individual to be fair.
OTC