First off, I think it's a tragedy that you're excluding the great early D&D modules Keep On The Borderlands and The Lost City. In my opinion, B4, The Lost City is probably the most perfect representation of what old D&D was all about.
D1-2 Descent Into the Depths
G1-2-3 Against the Giants
I purchased the original edition in which copies of these adventures when they were bound separately.
D3 Vault of the Drow
The D/G series is pretty great -- a just the correct amount of plot overlaid on hours and hours of killing things and taking their stuff.
S2 White Plume Mountain
Although flavoured slightly differently, this is a great example of a nice, short AD&D feel adventure that has just the right amount of campiness for first edition.
I2 Tomb of the Lizard King
Aside from being a tad linear, this is, I think, the most underrated of all modules. It was simply a great adventure -- weird, interesting, combat heavy and easy to strip into an existing campaign as a one-off.
N1 Against the Cult of the Reptile God
U1 Sinister Secret of Saltmarsh
These adventures are great in that they represent the first really successful attempts to get the dungeon above ground without losing its basic feel.