Everyone has their own favorite and harsh words have been exchanged on forums debating which one is best. The most often referenced are from Wilson, McCormick, Tripp, Metalform, and Check-Mate.
I have used them all in almost 50 years of carrying 1911s professionally and for fun. They all have strengths and weaknesses. They all work.
My personal favorite for the past decade or so is the
Check-Mate 8 round, extended tube, hybrid feed lip, removable baseplate, CMI follower mag. Some years ago I ran a 5,000 round feeding test using magazines from all the manufacturers listed above and others, factory ammo (FMJ, JHP) from all the major manufacturers, my own HG68 style reloads, and a dozen 1911s of all sizes from Colt and Springfield as well as my own home built ones. At the end of the test the results were conclusive. The 8 round Check-Mates fed when none of the others would and they fed noticeably more smoothly. But they're not for everyone. Be thankful we have a mostly free market economy and can pic from a wide variety of products.
Thunder Mountain is a veteran owned business that sells magazines from Tripp, Metalform, and Check-Mate. Excellent prices and super fast shipping. I highly recommend Mike.
Top Gun Supply also sells mags from Mec-Gar and Wilson.
If you want GI looking 7 round mags with the GI tapered feed lips your choices are few.
Check-Mate makes them but I don't care for them. I leave it up to others to make recommendations for GI mags.
I like 8 round mags. The very best 8 round mags (in my experience) are the
TMC Ultimate mags that utilize the Check-Mate 8 round magazine tube with the Tripp follower and spring. They are completely tuned and deburred. The only reason I don't have 50 of these is because they hadn't yet been invented when I did my 5,000 round test.