Prices on USGI (aluminum) and SA80 (steel) are really dropping lately, with the uncertainty of the AWB being renewed a lot of dealers are dumping their inventory. This is good if you need some mags right now, but if you're looking to stockpile them I would wait till the ban goes away and NIW USGIs are $10 each. I know, I know... but I'm an optimist.
As far as mags go, anything USGI is good, as are the British SA80's. I have a dozen or so Thermold mags, I've never had a problem with them and they have a good reputation... Just avoid the canadian versions with the maple leaf molded into the side; they were made with an inferior plastic that melts much more readily than the regular thermolds.
Orlites are Isreali mags that are kinda like wolf ammo; some swear by them, others hate 'em. I think that if you try them and they are reliable in you guns then who cares? But I wouldn't keep them for my SHTF stash.
And then there's USA brand mags... if they work I say use them for range mags. But do you really want to be seen with them?