Rasdale Stamp Company
Sells U.S. and worldwide issues and covers.
http://www.rasdalestamps.com/

Stamps-pl
Specializes in sales of Polish issues.
http://www.stamps-pl.com/

Corbitts
British firm sells postage issues, plus coins and other collectibles.
http://www.corbitts.com/

Schuyler Rumsey Philatelic Auctions
Sells U.S. covers and issues, plus British Commonwealth and other worldwide material.
http://www.rumseyauctions.com/

Tel-Aviv Stamps
Specializes in Israeli and Palestinian issues.
http://telavivstamps.stampcircuit.com/

Negev Holyland Stamps Auctions
Specializes in issues and postal history of Israel and Palestine.
http://negev.stampcircuit.com/

Olof Linder Stamp Catalogue
Features singles and sets from Sweden and other Scandinavian countries, plus other worldwide issues.
http://www.filateli.com/

Stamp Auction Network
Multiple dealers sell worldwide issues and lots.
http://www.stampauctionnetwork.com/

Cavendish Auctioneers
Specializes in sales of British Commonwealth and other worldwide issues and lots, plus related literature.
http://www.cavendish-auctions.com/

County Philatelic Auctions
Offers British Commonwealth and other worldwide issues and lots, plus conducts regular sales.
http://www.stampauctions.co.uk/

Regency Stamps
Sells worldwide issues and sports memorabilia.
http://www.regencystamps.com/

Northland Auctions
Deals in Scandinavian, U.S., and other worldwide issues.
http://www.northstamp.com/

Sandafayre
Covers British Commonwealth and other worldwide issues and lots.
http://www.sandafayre.com/

Cherrystone Auctions
New York company specializes in postal history, rarities, and other worldwide issues.
http://www.cherrystoneauctions.com/

Stamps by Themes
Specializes in French, Hungarian, and North Korean imperforates and other worldwide thematic issues.
http://www.stampsbythemes.com/

Delcampe
Collectors and dealers buy and sell worldwide issues.
http://stamps.delcampe.com/

Raritan Stamps
Offers worldwide issues and postal history with an emphasis on Russian material.
http://www.raritanstamps.com/

Philatino
Professional dealers sell worldwide issues, including rare stamps. Also offer forums and a newsletter.
http://www.philatino.com/

Northwestern Philatelic Auctions
Publishes six catologues each year featuring issues of Canada and Canadian provinces, plus other British Commonwealth material from around the world.
http://www.northwesternauctions.com/

AB Philea
Sells Scandinavian and other worldwide issues on monthly basis.
http://www.philea.se/

Status International
Sells Australian issues and other worldwide lots.
http://www.statusint.com/

Vance Auctions
Offers Canadian and British Commonwealth issues and other worldwide lots.
http://www.vanceauctions.com/

Stamp Head Auctions
Allows collectors to buy and sell postal material and supplies.
http://www.stamphead.com/

Prestige Philately
Offers Australian issues and other worldwide lots.
http://www.prestigephilately.com/

Black Swan Postal Sales
Sells issues and covers of the British Commonwealth.
http://www.bsps.freeserve.co.uk/

Philangles
Sells mint and used worldwide issues, covers, and lots.
http://www.philangles.co.uk/

Treasure-Hunters Limited
Specializes in issues of China and other Asian countries.
http://www.treasure-hunters.com.hk/

StampOffers.com
Allows collectors to buy and sell lots.
http://www.stampoffers.com/

Hans Grobe
Specializes in issues and postal history of Germany.
http://www.hans-grobe.de/

Robert E. Lippert Stamp Auctions
Specializes in U.S. issues and covers, plus other worldwide lots and collectibles.
http://www.relippert.com/

Robert A. Siegel
Specializes in U.S. classic issues, covers, and lots.
http://www.siegelauctions.com/

Stamp Wants
Dealers and collectors can buy and sell U.S. and worldwide issues.
http://www.stampwants.com/

Downeast Stamps
Sells U.S. issues and postal history, plus worldwide lots.
http://www.destamps.com/

H. J. W. Daugherty
Specializes in U.S. BOB issues and covers, plus related paper materials.
http://www.hjwdonline.com/

Nutmeg Stamp Sales
Specializes in U.S. postal history and classic issues.
http://www.nutmegstamp.com/

London Stamp Exchange
Specializes in postal history of the British Commonwealth, plus European and South American countries.
http://www.londonstampex.com/

George Alevizos
Sells lots including worldwide issues and covers.
http://www.georgealevizos.com/

Matthew Bennett International
Offers worldwide postal history and classics.
http://www.bennettstamps.com/

e-Stamp Auctions
Offers worldwide lots.
http://www.estampauctions.com/

Dennis R. Abel Stamps for Collectors
Offers U.S., UN and other worldwide issues and lots.
http://www.drabel.com/

Philatelic Friends
Specializes in South African and Rhodesian issues, postal history, and related material.
http://www.philatelicfriends.co.za/

Unistamps
Features issues and postal history of Europe, the British Commonwealth, and other worldwide nations.
http://users.actcom.co.il/unistamps/

Southampton Philatelic Auctions
Features issues of Great Britain and the British Commonwealth, plus other worldwide material.
http://www.sotonphil.co.uk/