Norway or Iceland for our one big Nordic trip - how do we choose?

We’ve dreamed about a Nordic trip for years and can finally do it, but only one this time, and I’m scared of choosing wrong. We want fjords and drama, a comfortable pace, and a shot at the northern lights. For those who’ve done both, which would you send us to first - and did the other one nag at you afterwards?

I would choose Iceland! It’s majestic