Layovers
Most layovers are 24 hours ! Only ULR flights are over that limit : LAX, SFO, IAH, YYZ are all over 48 hours . SYD is 48 hours when you do the long pairing DXB-BKK-SYD-CHC-SYD-BKK-DXB 24 hours in each stop except the second stop in SYD is 48 hours. If you are on the A380 you have the chance to go in the same city often this giving you a chance to visit more things each time.
Besides charter airlines who do international routes, I don't know any other major airlines that do long layovers .
Good Luck