The mathematically optimal repayment order is highest interest rate first, and almost nobody finishes that way. This list is ordered by how likely a demoralised reader is to reach the end of the plan, which is why Ramsey's snowball leads despite costing slightly more in interest. Sethi follows because automation removes willpower from the loop entirely. Collins, Lowry, and Aliche are each here for a specific reader the first two miss: the reader who wants brevity, the reader with student loans and thin credit, and the reader whose last attempt was wrecked by an emergency.
Snowball or avalanche — which should I use?
Avalanche costs less; snowball gets finished more often. If you have abandoned a payoff plan before, use the snowball and accept the small extra interest as the price of completing it.
Which book if I have student loans specifically?
Broke Millennial. Lowry covers thin credit files, repayment plan selection, and the conversations around family money that the other four skip.
Should I save or pay off debt first?
A small emergency buffer first, then debt, then real savings — Aliche makes this case best. Paying off a balance with no buffer usually ends with the balance back on the card after the first unexpected expense.
Is any of this advice, formally?
No. Everything here is a book review. Nothing on this site is financial advice, and none of these authors know your situation, tax position, or interest rates.