Well, you mentioned "North Korea still builds nuclear weapons," but didn't mention Iran having them. So, something worked. It wasn't 100% just sanctions... But the sanctions certainly hampered their ability to acquire effective air defense.
(The NK sanctions were too late — NK had already started nuclear weapons testing before the sanctions were levied.)
Off the top of my head: I don't think the USSR is still around, and it largely collapsed due to economic pressure; Libya abandoned its nuclear program due to sanctions; and apartheid in South Africa ended largely due to sanctions.
They don't always work, but I've never heard of jeans and heavy metal working either, as nice as that would be. Belarus has plenty of both, but Lukashenko's been in power since the 90s.