I mostly write e-mail copy so my influences in that area include:

1.) Jay White
2.) Frank Kern
3.) Harlan Kilstein
4.) Jason Moffatt
5.) Matt Furey

Others:

6.) Herschell Gordon Lewis (for both sales letters and catalog copy)
7.) Ted Nicholas

Honorable mentions to Mr. Subtle, for lessons in pithisizing and design, and Jason Leister, for instruction in how to market copywriting services.

--Anita