Marvel’s Amazing Spider-Man #666 topped sales of periodical comics in July with sales through Diamond Comic Distributors estimated by ICv2 at 135,568 based on sales indexes released by Diamond.  ASM #666 was the only title in July with sales of over 100,000 copies.  In addition to the devilish cachet of its issue number, Amazing Spider-Man #666 functioned as the Prelude to the “Spider Island” storyline, but its month-leading total also could be in part the result of Marvel’s custom variants program that featured a store’s image or logo for those retail organizations that ordered 500 copies.
Marvel’s Captain America #1, which is written by Ed Brubaker and was helped by oodles of variant covers may be also got at least a small boost from the successful debut of the Captain America: The First Avenger film on July 22nd, was the #2 title with an estimated 96, 926. Marvel’s Fear Itself #4, the publisher’s big summer comic event was down just over 2% with an estimated 93,435, which was good enough for the #3 spot.  Marvel also managed to place 4 Fear Itself tie-ins (Avengers #15, New Avengers #14, Uncanny X-Men #540, and Uncanny X-Men #541) in the top 25.
DC Comics’ top title was the event related Flashpoint #3, which dropped just 1.7% and finished at #4 with an estimated circulation of 86,007 copies. 
Marvel took the top three spots and 15 of the top 25. DC increased its share of the top 25 titles from 8 in June to 10 in July.  Fourteen titles in the top 25 suffered circulation declines while six posted increases, and there were five number one issues including a new Daredevil series written by Mark Waid that finished at #6 (aided by a slew of order incentive variant covers), and X-Men: Schism #1, the main book of the big summer X-event that debuted somewhat disappointingly at #11 with issue #2 ending up at #28 with sales some 13,000 copies below the first issue.
On the graphic novel side Top Shelf’s League of Extraordinary Gentlemen written by Alan Moore sold three times as many copies as the #2 title, Dark Horse’s Conan the Barbarian: Mask of Archeron.  Top Shelf’s LOEG gave the market a title with sales of over 20,000 copies for the second month in a row. Vol. 14 of Robert Kirkman’s The Walking Dead accomplished the same feat in June, though it must be said that Kirkman’s volume has real heft whereas the LOEG and Conan books qualify more as “slim-line” graphic novels with lower page counts (and price points) than the typical graphic novels.
The long-awaited softcover debut of Mark Millar’s Kick-Ass from Marvel was the #3 book of the month, but DC dominated the graphic novel top 25 thanks in part to the paperback debut of seven Blackest Night titles which came out a full 12 months after the Blackest Night hardcover editions debuted.
Overall DC had 12 of the top 25 graphic novel titles, followed by Marvel with six, Dark Horse with 3 (including 2 Star Wars books), IDW with 2 (Volumes 3&4 of Joe Hill’s Locke & Key), followed by Top Shelf (LOEG) and Image (The Walking Dead Vol. 14 came in at #11) with one each.
Viz Media’s Yu-Gi-Oh! 5Ds Vol. 1 was the bestselling manga in the direct market at #36.
Here are ICv2’s estimates for the sales by Diamond Comic Distributors to comic stores on the Top 25 comic titles in July of 2011:
135,568                      Amazing Spider-Man #666
 96,926                       Captain America #1
 93,435                       Fear Itself #4
 86,007                       Flashpoint #3
 74,521                       Green Lantern #67
 64,866                       Daredevil #1
 62,792                       Batman the Dark Knight #3
 62,580                       Avengers #15
 61,166                       War of the Green Lanterns Aftermath #1
 60,836                       Green Lantern Corps #61
 58,326                       X-Men: Schism #1
 58,306                       New Avengers #14
 57,928                       Green Lantern Corps #62
 57,333                       Batman the Dark Knight #4
 57,206                       Uncanny X-Men #540
 56,948                       Amazing Spider-Man #665
 55,856                       Uncanny X-Men #541
 55,601                       FF #6
 55,413                       Uncanny X-Force #12
 55,172                       Batman and Robin #25
 54,022                       FF #7
 51,385                       Batman #712
 51,187                       Captain America & Bucky #620
 49,084                       Ultimate Comics Fallout #1
 48,087                       Green Lantern Emerald Warriors #12
For an analysis of the dollar trends in July, see "Comics Down Again in July."

For our estimates of actual sales by Diamond U.S. from comic specialty stores on comic books shipped during July, see "Top 300 Comics Actual--July 2011."

For our estimates of actual sales by Diamond U.S. from comic specialty stores on graphic novels shipped during July, see "Top 300 Graphic Novels Actual--July 2011."

For our estimates of actual sales by Diamond U.S. from comic specialty stores on comic books shipped during June, see "Top 300 Comics Actual--June 2011."

For our estimates of actual sales by Diamond U.S. from comic specialty stores on graphic novels shipped during June, see "Top 300 Graphic Novels Actual--June 2011."

For an overview and analysis of the best-selling comics and graphic novels in June, see "Death of Spider-Man Tops 139K"  For an analysis of the dollar trends in June, see "Comics' Slide Continues in June."

For our index to our reports on the top comic and graphic novel preorders for January 2000 through July 2011, see "ICv2's Top 300 Comics and Top 300 GNs Index."