I love Joy Division and the first 2 New Order albums - it all got a bit pop after that.
Lyrically Ian Curtis was a genius IMO - I used to joke that I listened to Joy Division when I needed reassurance that there were others having a harder time than me.
Unknown Pleasures was raw but promising then came Closer, an almost perfect album, a masterpiece.
When Closer came out it was different, cold, disturbing music the like of which had never really been heard - like Neil Young brought into the post punk era...
Joy Division have influenced so many acts that have followed that they probably don't have the same impact on someone listening to them now for the first time.
Joy Division are, to me, the most important band to come from the post punk era.