Above all; more than anything else—used to stress the most important point.
何より健康が大事だから、無理はしないでください。
Above all, your health is important, so don't overdo it.
彼の成功は、何より努力の結果だ。
His success is, above all, the result of hard work.
何よりもまず、計画を立て直そう。
First and foremost, let's reorganize the plan.
The best; excellent; used as a noun/adjective phrase meaning 'the greatest' or 'most suitable'.
君の成功が私には何よりの喜びだ。
Your success is the greatest joy for me.
このプレゼントは彼女にとって何よりの励みになるはずだ。
This present should be the greatest encouragement for her.