Here's something I researched the other day:
1) Original
Chainmail/D&D 3book set/five supplements (BM, GH, EW, GDH, S&S)
2) D&D basic 1
(blue book) (edited by Holmes)
3) Advanced D&D
(PHB, DMG, MM, De&De, FF, MM2, UA, OA)
4) D&D basic 2
D&D basic 2(Otus covers - magenta box) (edited by Moldvay)
D&D expert 1(Otus covers - light blue box) (edited by Dave Cook)
5) D&D basic 3
D&D basic 3(Elmore covers - red box) (edited by Mentzer)
D&D expert 2(Elmore covers -dark blue box) (edited by Mentzer)
D&D companion (Elmore covers - light blue box) (by Mentzer)
D&D Master (Elmore covers - black box) (by Gygax & Mentzer)
D&D Immortals (Elmore covers - gold box) (by Mentzer)
6) D&D Cyclopedia hardcover
(Easley cover) by Aaron Allston (essentially expert revision 3)
7) Advanced D&D 1.5
(not really separate but noting the major shift in direction post-Gygax) DragLance Adv, Greyhawk Adv, Dungeoneer's SG, Wilderness SG, Manual of the Planes
8)Advanced D&D second edition
(PHB, DMG, ToM, BoA, MonComps, Complete series, historical series, FR Adv)
9)Basic Set 4
(black box then full color then black again) "New Easy to Master D&D" later changed to "Classic D&D"
10)Dark Sun campaign setting
(definitely another version)
11)Advanced D&D 2.5
the option hardcover years
12)Third Edition Dungeons and Dragons
13)Hackmaster (PHB, GMG, Monster books)
I don't feel funny about someone's opinion of the original Advanced game but I do feel funny when they call the 12th edition the 3rd edition!
;P