Magpul Gen 2s and 3s work well. Both have polymer feed lips though if that bothers you. Gen 2s used to ship with a cover that could clip onto the top of the mag to press down on the top round to relieve pressure on the lips because there were some instances of feed lips cracking. I haven't had any crack personally. The newer ones I've bought have not included the covers.

Lancer mags are polymer mags with metal feed lips. They've worked well for me too.

D&H mags from PSA are my favorite metal GI mags and the price is on par or better than most other options. They have anti-tilt followers. One thing I like is that the edges are not as sharp as some other GI mags I have.

Okay Industries Surefeed and Surefeed E2 mags both work well too and come with anti-tilt followers. The black and tan magazines are Teflon coated, but the last batch I bought had some sharp edges. YMMV.