While I generally prefer polymer magazines like the Bulgarian Circle 10 and US Palm AK30 for my AK-47s, I still keep a stash of metal mags on hand. Most of my metal magazines are of the Chinese Smooth Back (no rib) variety because I greatly prefer the handling characteristics of these mags. There is no sharp rib on the back to tear your hands over a long day at the range.
These magazines can be hard to find so I like to point them out when I see them. SG Ammo has several of them in stock at a great price.