Haybales!
Meh, I don't really like luck tasks. Here's the ones that could be reused though.
Eiffel Tower RB (point to somewhere else, though)
Paris detour (though it's hard to duplicate this)
Tunisia Colisseum RB
Listening or Puzzling
Sahara RB
Confusion Now or Confusion Later
Aussie Slang RB
Cool Down or Heat Up
Boomerang RB
Scotland RB
Count the Money or Run the Numbers
William Tell RB
Swiss Bike RB
Basket Boats or Basket Bikes
Search or Rescue
Waterway or Pathway
Venice RB
Mozart or Beethoven
Malaysian Archery RB
Seoul RB
Seoul Detour (somewhat reused in Asia)
Hawaii RB
Perro or Tango
Block 5 Shots or Drink 1 Shot
Caviar RB
Zorb RB (but make it harder)
Plow or Fowl (I want to see both options though, so let's have a double RB!)
Ice Climb or Ice Search
Endurance or Accuracy
Haybales has already been reused
Hungarian Soup RB
All Ethiopia tasks
Locks RB (it's just too memorable)
Argentina Meat RB (also memorable)
All the Africa tasks this season
Istanbul RB
All London tasks
Limbo RB
Italy Statue RB
All Greece, Oman, and Australia tasks
The final RB
I can go on if you want.