Joy Division is terrific, along with many of the other post-punk bands of the same era, including (with suggested album in parenthesis):
Pere Ubu (Modern Dance)
Gang of Four (Entertainment)
Minutemen (Double Nickels on the Dime)
Wire (Pink Flag)
The Slits (Cut)
Public Image Lit (First Edition, Second Edition)
Frank Hell and the Voidoids (Blank Generation)
The Pop Group (Y)
Most of these recommendations come straight from gavin friday. at a dinner in dublin i sat next to him and spent an incredible hour taking a crash course in music history. all of the above are outstanding classics of the era.
Other misc. recommendations:
The Mekons (Rock n' Roll)
Wilco (all four)
Uncle Tupelo
Big Star (Radio City<--absolutely incredible)
Love (Forever Changes)
Pavement (Crooked Rain, Crooked Rain)
Flaming Lips (Soft Bulletin, Yoshimi Battles the Pink Robot)
Leonard Cohen (Songs of Love and Hate)
Van Morrison (Astral Weeks)
Buzzcocks (Singles Going Steady)
The dB's (Stands for Decibels)
etc etc etc.