CONCENTRATION
 

    (MB 1958) Twenty-four editions, plus an Educational Edition (1964)
The last edition published was the Silver Anniversary 25th Edition, but bowing to superstition, MB never released a 13th Edition.  As with Password, the later editions are often harder to find than the earlier ones.  MB also sold Puzzle Roll #3 (1960) separately between the releases of the second and third editions.  That roll of rebus puzzles is extremely rare today.
    (Pressman 1988) Classic Concentration
    (Endless Games 1998)
In 2003, Endless Games rereleased their version in new packaging and with different prizes, however the rebuses remained the same.  The rebuses in the Endless Games version were designed by Steve Ryan, who created the rebuses used on Classic Concentration.


    (Softie 1988) Classic Concentration Two editions
Graphics on these early computer versions are crude by today's standards, which makes these games hard to enjoy.
    (Mumbo Jumbo 2007)
A modern update with snazzier graphics, licensed by NBC's parent company and therefore legit, this version has rebuses that are pretty simplistic even by Classic Concentration standards but is otherwise reasonably faithful to that version.


    (GameTek 1990) Classic Concentration for Nintendo NES


    (Tiger 1999)
The handheld version comes with a sixteen-tile grid, simple rebuses to solve and a bonus round.
 

    (Horne 1971) Three issues
Each issue of this collection featured 36 rebus puzzles, 30 standard and six extremely challenging "super" puzzles, as well as introductory comments from show producer Norman Blumenthal.


    (Pyramid 1976) Scramble by Norman Blumenthal 
After the original series' cancellation, Blumenthal released this paperback pocket book of rebus puzzles which isn't an "official" Concentration product but should still be interesting to the show's fans.  No less a source than Mr. Blumenthal himself tells us there was a Scramble Junior, but no other volumes in the proposed series.
    (Sterling 1991) Classic Concentration by Steve Ryan
A collection of 152 rebus puzzles from the series, plus a history of the original show richly illustrated with many classic photos.  Ryan created all the Classic Concentration rebuses used on the show.