The following ISBN ranges have at least 500 books/other media listed in this site:

HarperCollins
0-02
0-03
0-04
HarperCollins
McGraw-Hill
Elsevier
Random House
Stationery Office Books
Academic Press
Prentice Hall
Penguin Books Ltd
0-15
0-16
Oxford University Press
Addison-Wesley
Routledge
Allyn & Bacon
Jonathan Cape Ltd
University Of Chicago Press
Palgrave Macmillan
Columbia University Press
Focal Press
University of Illinois Press
Indiana University Press
The MIT Press
Harlequin Mills & Boon
Financial Times/ Prentice Hall
Praeger Publishers
University of Texas Press
University of Washington Press
Weidenfeld & Nicolson
University of Wisconsin Press
Yale University Press
0-304
Da Capo Press
0-307
Zondervan
St. Martin's Press
Greenwood Press
West
Hachette Book Group USA
Ordnance Survey
0-321
Mosby
South-Western College Pub
0-330
Palgrave Macmillan
Open University Press
0-340
Ballantine Books
Abacus
0-352
Harlequin Books
Farrar, Straus and Giroux
0-375
Avon
0-385
Springer
W.W. Norton & Co.
Random House
Houghton Mifflin
Penguin Putnam
Methuen Drama
Routledge
Berkley
Heinemann Library
William Heinemann Ltd
Heinemann Educational Publishers
Scholastic
Dell
Ace
Churchill Livingstone
Elsevier Science
0-446
Grosset & Dunlap
Fawcett
Signet
Plume
Basic Books
John Wiley & Sons
John Wiley & Sons
University of Michigan Press
Dover Publications
Wadsworth Publishing
Thames & Hudson
Jove
Children's Press(CT)
0-517
University of California Press
Cambridge University Press
0-525
Children's Press(CT)
Wadsworth Publishing
Scholastic
Kessinger Publishing, LLC
Corgi Books
Bantam
BBC
Faber and Faber
Gollancz
Longman
0-586
Scholastic
Bantam Press
iUniverse, Inc.
O'Reilly Media, Inc.
Hamlyn
0-609
Topeka Bindery
Houghton Mifflin
Course Technology
WileyBlackwell
WileyBlackwell
Hal Leonard Corporation
Westminster John Knox Press
0-670
0-671
Sams
Harvard University Press
0-676
0-679
0-684
Abingdon Press
0-688
0-689
Princeton University Press
0-696
University Press of Kansas
Jane's Information Group
Ian Allan Ltd
Frances Lincoln
Music Sales
0-7126
Batsford Ltd
A & C Black Publishers Ltd
Routledge
Phaidon Press Ltd
David & Charles PLC
W.H.Freeman & Co Ltd
Michael Joseph Ltd
Manchester University Press
John Murray Publishers Ltd
Saunders
Aspen Publishers
Microsoft Press
Human Kinetics Publishers
Harvest House Publishers
0-7382
Arcadia Publishing
Llewellyn Publications
Random House Audio
Andrews McMeel Publishing
Rowman & Littlefield Publishers, Inc.
0-7432
0-7434
Simon & Schuster Audio
Walker Books Ltd
Pluto Press
Polity Press
Usborne Publishing Ltd
Headline
Bloomsbury Publishing PLC
Edinburgh University Press
Nelson Thornes
Kogan Page Ltd
Automobile Association
Franklin Watts
Piatkus Books
0-7506
The History Press Ltd
Dorling Kindersley Publishers Ltd
Time Warner Paperbacks
0-7524
Orion
Kingfisher Books Ltd
Virgin Books
Phoenix
Ashgate
Headline
0-7566
Kensington
Motorbooks
Workman Publishing Company
Prima Games
0-7619
Running Press
0-7627
Candlewick
Jones & Bartlett Publishers
Barron's Educational Series
Bethany House
Schiffer Publishing
John Wiley & Sons
0-7653
Kessinger Publishing
Delmar Cengage Learning
Broadway
Peterson's
McClelland & Stewart
Edwin Mellen Pr
McGill-Queen's University Press
Mira
Institute of Electrical & Electronics Enginee
Lippincott Williams & Wilkins
Sybex
Marvel Comics
Thomas Nelson
Blackstone Audiobooks
Thorndike Press
McFarland & Company
0-7867
Hyperion
Wizards of the Coast
0-7876
Jossey-Bass
Routledge
Universe Publishing
0-7894
Que
State University of New York Press
National Geographic
Springer
Hal Leonard Corporation
Usborne Books
Augsburg Fortress Publishers
Revell
0-8010
Cornell University Press
The Johns Hopkins University Press
University of Toronto Press
Grove Press
Moody Publishers
Walker & Company
Wm. B. Eerdmans Publishing Company
University of Nebraska Press
Sage Publications, Inc
Stanford University Press
Tuttle Publishing
0-8050
B&H Publishing Group
Lawrence Erlbaum
University of Oklahoma Press
Citadel
Beacon Press
Louisiana State University Press
Teachers College Press
The University of North Carolina Press
Paulist Press
The Scarecrow Press, Inc.
Harry N. Abrams
Stackpole Books
Chronicle Books
University of Pennsylvania Press
0-8125
0-8129
Westview Press
Rutgers University Press
AMACOM
NYU Press
Brookings Institution Press
Facts on File
University of Minnesota Press
SPIE-International Society for Optical Engine
Peter Lang Publishing
Zebra
Cliffs Notes
Duke University Press
Watson-Guptill
CRC
University of Hawaii Press
University of New Mexico Press
Continuum
InterVarsity Press
Bentley Publishers
Tyndale House Publishers
Leisure Books
Rizzoli
CRC
Thomas Nelson
Krause Publications
DAW
0-89281
1-4000
Tantor Media
1-4012
Hyperion
Delmar Cengage Learning
Hay House
Springer
Sourcebooks, Inc.
Sterling
Palgrave Macmillan
Macmillan
WileyBlackwell
Egmont Books Ltd
Dorling Kindersley
1-4058
Lulu.com
1-4129
Xlibris Corporation
PublishAmerica
Saunders
1-4165
1-4169
Topeka Bindery
Kessinger Publishing, LLC
Kessinger Publishing
Kaplan Publishing
BookSurge Publishing
CRC
AuthorHouse
VIZ Media LLC
1st World Library - Literary Society
IndyPublish.com
1-4233
Hal Leonard Corporation
TokyoPop
1-4391
1-55468
1-56025
Fantagraphics Books
Taunton
DC Comics
Martingale and Company
Dark Horse
Collector Books
North Light Books
Image Comics
1-58663
Two-Can Publishing, Inc.
Humana Press
Apress
VIZ Media LLC
TokyoPop
The Lyons Press
Dark Horse
TokyoPop
1st World Library - Literary Society
TokyoPop
Lonely Planet Publications
Titan Books Ltd
Orbit
Osprey Publishing
Jessica Kingsley Publishers
Letts Educational
Rough Guides
1-84415
Black Library
Titan Books Ltd
Quercus Publishing Plc
The Crowood Press Ltd
The Crowood Press Ltd
Hachette
Seuil
Larousse
Bordas
Michelin Editions des Voyages
Gallimard
Flammarion
2-09
Dunod
Presses Universitaires de France - PUF
Armand Colin
Casterman
Dargaud
Denoël
Magnard
L'Ecole des loisirs
Eyrolles
Fayard
Fleurus
Foucher
Hatier
Robert Laffont
Albin Michel
Payot
Grasset
Dalloz-Sirey
LGF - Livre de Poche
Presses de la Cité
Plon
Librairie Académique Perrin
10
Fleuve Noir
Pocket
Editions du Rocher
Harlequin
J'ai lu
Masson
Marabout
Belin
La Découverte
Editions d'Organisation
Vuibert
Economica
Glénat
Ellipses Marketing
Odile Jacob
Actes Sud
Rivages
2-7440
Milan Jeunesse
Bayard Jeunesse
Delcourt
Dupuis
Le Lombard
2-84538
Pika Edition
Kana
Chouette
岩波書店
朝日新聞社
角川書店
学習研究社
講談社
集英社
小学館
新潮社
中央公論新社
日本放送出版協会
早川書房
文藝春秋
徳間書店
河出書房新社
光文社
幻冬舎
ダイヤモンド社
筑摩書房
東洋経済新報社
日本経済新聞社
PHP研究所
白泉社
扶桑社
スクウェア・エニックス
エンターブレイン
講談社インターナショナル
技術評論社
宝島社
ソフトバンククリエイティブ
翔泳社
中経出版
竹書房
日経BP社
富士見書房
福音館書店
三笠書房
メディアワークス
5-550
Alianza Editorial Sa
Gredos
Brill Academic Publishers