B1 In Search of the Unknown by Mike Carr
B2 Keep on the Borderlands by Gary Gygax
B3 Palace of the Silver Princess by Tom Moldvay and Jean Wells
B4 Lost City by Tom Moldvay
B5 Horror on the Hill by Douglas Niles
B6 Veiled Society by David Cook
B7 Rahasia by Tracy and Laura Hickman
B8 Journey to the Rock by Michael Malone
B9 Castle Caldwell and Beyond by Harry Nuckols
B10 Night's Dark Terror by Jim Bambra, Graeme Morris, and Phil Gallagher
B11 King's Festival by Carl Sargent
B12 Queen's Harvest by Carl Sargent
BSOLO Ghost of Lion Castle by Merle Rasmussen

Modules B1 - B9 were later compiled into supermodule B1-9 In Search of Adventure.

Some copies of B1, B2, B3, and B4 were 3-hole-punched at the factory.

The working title for B4 Lost City was "The Lost City of Cynidecia".

B6 Veiled Society includes cardstock miniatures and 16 pages of fold-together buildings.

B10 Night's Dark Terror is a "bridge" module between the Basic and Expert D&D sets.  Includes a large, 2' x 3' fold-out map and 120 cardboard counters.  Thanks to James Caldwell for help with this info.

B12 Queen's Harvest is the sequel to B11 King's Festival.  The cover artwork would later be recycled for the cover of WGQ1 Patriots of Ulek (thanks to Raymond Lugo for noticing this!)

Printing Information

The 3-hole-punching on some of the early B-series modules does seem to indicate a different printing (probably earlier), but this is not proven.

The scarcity of these modules increases sequentially; modules B1 - B6 are fairly common, while B10 - B12 are somewhat rare.  This is probably due to diminishing print runs as time went on.

The different printings of B1, B2, B3, and B7 can be accessed through these links.  Otherwise, only B4 Lost City has any distinguishable printings.

B10 Night's Dark Terror has a UK version, which is identical in all respects to the US version except it has a "B/X1" sticker over the "B10" code on the front cover.  TSR UK, who developed the module, originally intended it to bear the B/X1 code (since the module is a bridge between the Basic and Expert sets), but were overruled by TSR USA.  The "B/X1" version is substantially rarer than the "B10" version. (Thanks to Graeme Morris and Bill Wilkerson for this info).

B4 Lost City

• First (1982):  Angled yellow banner in upper left.  TSR Face logo.  ISBN on back cover bottom left, Product Number (394-52498-5TSR0550) back cover bottom right.
  
  
• Second:  Contents identical to First, but has a cardboard header stapled to the top of the module, with the D&D logo and some other advertising.  Note that the module itself, separated from the header, is indistinguishable from a First print.  (Thanks to Michael Deaton for this info).  Further info on header modules is here.
  
  
• Third:  Angled yellow banner in upper left.  TSR Face logo.  ISBN is centered on the back cover bottom, and Piece Code (9049XXX1401) is on back cover bottom right instead of the Product Number.
  
  
• Fourth (1983?):  Red banner across top and more modern "Dungeons & Dragons" logo.  Angled TSR logo.  ISBN and Product Number back cover bottom center, Piece Code back cover bottom left.  (Thanks to Michael Deaton for this info and the scan).

B5 Horror on the Hill
B6 Veiled Society
B8 Journey to the Rock
B9 Castle Caldwell and Beyond
B10 Night's Dark Terror
B11 King's Festival
B12 Queen's Harvest
BSOLO Ghost of Lion Castle

Thanks to Leonard Riotto for the scans of B5 and B6, and to Adrian Newman for the scan of BSOLO.

Lost City (1st/3rd print)	Lost City (4th print)	Horror on the Hill	Veiled Society	Journey to the Rock
Castle Caldwell & Beyond	Night's Dark Terror	King's Festival	Queen's Harvest	Ghost of Lion Castle

The Fourth print of B4 Lost City (with the red banner) appears to be more rare than the other prints. 

B10 Night's Dark Terror often fetches supermodule-high amounts at auction, most likely due to several reasons.  As contributor James Caldwell notes, besides the normal 64-pg module booklet, B10 also includes a large fold-out map (approx 2' x 3') and 120 cardboard counters.  A chapter of the module is a goblin siege of a homestead and the entire battle is played out on this remarkable map with the counters.  Additionally, as Dan Gioffre states, B10 provides a good deal of Mystara information (specifically the Grand Duchy of Karameikos) that is available nowhere else -- a boon to Mystara fans.