Thanks for posting this, Kyle. I would add 3 more, although the first two might not strictly be copywriting models:
1. Robert Cialdini (not a copywriter, but his book, Influence, is important
2. Chris Marlow (her Writer's Compensation Survey will leave you shocked at how much you're undercharging)
3. our good friend Jack Forde (This isn't mere flattery. If you know of any copywriting newsletter that's better than the Roundtable, I want to subscribe!)
These guys are all great. And worth studying. Gary, too, has had an influence (I've used "hang on there, Cupcake" in my own copy more than once).
But there are some other contemporaries, at least in the info publishing area, worth studying too.
For instance, I was lucky enough to work directly with two of the best -- Michael Masterson and Bill Bonner -- in an office, day to day, for about four years running. There are a couple copywriters I've worked with, too, that you're not going to know. Guys like Paul Hollingshead and Don Mahoney. Both have a style I've learned from, even as we worked on projects side by side.
I studied promos by Clayton Makepeace and Gary Bencievenga long before I got good enough myself to swap emails with them personally. There's also someone named Lee Euler whose copywriting style is generally brilliant.
Who else? I'm sure there are others. What occurs to me from the list, though, is that I learned from these guys not so much in their guru roles... but by studying the actual sales letters they had produced, over other people's signatures.
I guess what I'm saying is, there's a case to be made for learning not just from studying theory (which is very important), but also by studying application (just as critical).
I also subscribe to a few e-newsletters that help me stay fresh. And get a TON of magazines including Interview, oprah, Fortune, Forbes, Conde Nast Traveler, Maxim, Detail, Men's Health, Rolling Stones, Inc., Entreprenreur, Kiplingers, Family Circle (they have great headlines I can 'repurpose', believe it or not), Communication Arts, Wired, More, Real SImple--holy smoke. I get a lot. Even more than this, though I can't think of all of them. When I'm done I pass them along to the designers in my area and they're all snapped up in MINUTES. Everyone here has a tickler file/wonder drawer of ideas full of magazine tear sheets.