Question: what are the most important things to upgrade in clash of clans?
Answer: Heroes. Yes, Heroes. ... 
Storages, Laboratory. Storages are a very important upgrade for two reasons: bigger storages are necessary for certain upgrades and it's important to have more space to hold resources when all builders are busy. ... 
Clan Castle, Barracks, Army Camp, Spell Factory. ... 
Defenses. ... 
Town Hall. ... 
Walls.