1) MAB PA15-Built like a proverbial tank this all steel (I think even the magazine follower and baseplate were made out of steel), 15 round, semi-auto pistol with it's rotating barrel locking system was one of the most sweet shooting 9mm.s I ever shot. It was also overlooked and underrated by many shooters looking for a high capacity 9mm.
2) Star Models B, BM, and BKS-Three well built, slightly scaled down versions of the 1911. Very good, service grade semi-autos that few ever paid notice of when looking for a 9mm. Later the Star Models 28, 30, and 30 PK also had some interesting design features but were mostly non-existent in dealer's showcases.
3) HK 4-This innovative pistol could actually be converted into 4 different chamberings (.380, .32, .25, and .22), with just a barrel swap, recoil spring, and magazine (the breech plate was switched around to allow for converting the firing pin from centerfire to rimfire). Saw a few for sale at various gun shows over the years (usually the .380 with a .22 conversion kit; the 4 caliber set-up was priced up in the Stratosphere), this was a neat, pocket auto size, multi-purpose/multi-caliber gun that seemed to generate very little interest.