Teapot dome was trivial (only one cabinet official was convicted abd even he beat most of the charges), certainly no worse than trading hostages for arms. Harding deserves number one. He was not only great on economics but also far superior on foreign policy, civil liberties, and civil rights. Sorry to tell you (but Stockman has detailed) but Reagan wimped out on the spending and deficit issue when he should have taken out his veto pen.
Harding probably does deserve the #1 slot. No other modern President successfully ended a depression.