I like to follow the Keep It Functional Stupid philosophy.
Every personal defense carbine, to include the AK, needs the following:
1. Sling (A real two point sling like a quick-adjust Blue Force Gear, not a carrying strap). If all you have is the issued carrying strap, it's sufficient but not ideal. If you are on a SEAL team or Delta Force, you might need a single point, but I don't like having my carbine smash my knee caps.
2. Professional Grade Red Dot Optic (Aimpoint, EoTech, or Trijicon)
3. Professional Grade White Light (SureFire)
That's all you really need on any carbine. There's lots of cool toys like folding stocks, lasers, Picatinny rail hand guards, bipods, etc, but the stuff you really need on any personal defense carbine has been covered.
My AK has a Blue Force Gear quick adjust, an Aimpoint Comp M3, and a SureFire X300.