I expect the three 1000kg load will be the most popular. It kinda lacks utility though as it is total overkill for hangars, but probably pretty good at GV smashing. The three 500kg load would be just as good for hangars and allow improved climb and speed. The six 250kg loadout should also be useful for taking out radars, ammo dumps and barracks, but it will also completely eclipse the four 250kg loadout. The nine 100kg bombs and two 250kg? 500kg? bombs also seems like it might be a good mix, particularly if the two external bombs are 500kg.
Not sure what to make of the bottom right loadout. Maybe they are 500kg high capacity bombs? The label for the large finned 500kg bombs is "A6-500" (I know it isn't a 6, but that is the closest I can come to that symbol on my keyboard) and the label on the bottom right is "ABK-500".