I prefer higher levels, especially epic. Lower levels just aren't all that interesting to me, with their goblins and kobolds and local taverns needing the rats cleared out. They're too relatable, too small in scope, too mundane for me to enjoy to the fullest. The next tier up after that is hardly more interesting than the first, it's just a little bigger than the first what with instead of villages you got major cities and fiefdoms asking you and your party to help with the orc raid happening in a fortnight. The tier after that though starts to make things interesting, especially since at that point I feel PC's really begin to shine and become something more, and at this point the decisions of a party could affect an entire realm/nation.
Epic is well...epic, you could be facing demi-gods, dark armies hellbent on destroying everything, avatars of demon princes, real fate of the world in your hands type stuff. It's not that I cannot play in a lower level campaign, I just honestly don't enjoy lower levels all that much, too low power for me.
It's surprisingly difficult to write good adventures for the epic levels. Partly because there's very little inspirational material worth emulating when D&D style magic trivializes nearly every "epic" story. You generally end up just fighting a string of Big Bad CR's without any good context because all the great plots don't work when Wish/etc is around.
Just look at how many published adventures conveniently end by about 15.