Long time reader of the database and very appreciative of the amount of time put into keeping this project alive.  I was able to pick up a PX-755SA for 20 bucks, upgraded the firmware and would like to contribute to this database that I have used myself for a long time.  These are the physical copies I can contribute (just reading jewel case and disc/discs), once I finish more reading and make sure I am meeting the standard.

The titles highlighted in red are present in the missing titles lists.

[PSX]
Ace Combat (SLPS 00061)
Armored Core Master of Arena
-Disc 1 (SLPS 01855)
-Disc 2 (SLPS 01856)
Armored Core Project Phantasma (SLPS 01130)
Bomberman World Playstation the Best for Family (SLPS 91149)
Bomberman Fantasy Race (SLPS 01525)
Bushido Blade (SLPM 86020)
Chocobo Racing Genkai E No Road (SLPS 01951)
Chocobo Stallion (SLPS 02520)
Dance Dance Revolution (SLPM 86222)
Dance Dance Revolution 2nd Remix (SLPM 86252)
Dance Dance Revolution 2nd Remix Append Club Version Vol. 1 (SLPM 86370)
Dance Dance Revolution 3rd Mix (SLPM 86503)
Final Fantasy VII
-Disc 1 (SLPS 00700)
-Disc 2 (SLPS 00701)
-Disc 3 (SLPS 00702)
Final Fantasy VII International
-Disc 1 (SLPM 87380)
-Disc 2 (SLPM 87381)
-Disc 3 (SLPM 87382)
-Disc 4 (SLPM 87383)
Final Fantasy IX
-Disc 1 (SLPS 02000)
-Disc 2 (SLPS 02001)
-Disc 3 (SLPS 02002)
-Disc 4 (SLPS 02003)
Metal Gear Solid Integral
-Disc 1 (SLPM 86470)
-Disc 2 (SLPM 86471)
-Disc 3 (SLPM 86472)
Mobile Suit Gundam (SLPS 00035)
Mobile Suit Gundam Char's Counterattack (SLPS 01724)
Soviet Strike (SLUS 00061)
Tekken (SLPS 00040)
Tekken 2 (SLPS 00300) - I have 2 physical copies
Tekken 3 (SLPS 01300)

[PS2]
Dance Dance Revolution Extreme 2 (SLUS 21174)
Dance Dance Revolution Supernova (SLUS 21377)
Dance Dance Revolution Supernova 2 (SLUS 21608)
DDRMAX 2 (SLUS 20711)
Densha De Go! Professional 2 Taito Best (SLPM 65661)
Densha De Go! 3
-Disc 1 (SLPM 62049)
-Disc 2 (SLPM 62050)
Densha De Go! Final (SLPM 65590)
DOA2 Hardcore (SLPS 25026)
Metal Gear Solid 2 Substance (SLPM 67002)
Soul Calibur II (SLPS 25230)
Superlite 2000 Tokyo Bus Annai 2 (SLPM 66555)
Wild Arms 3 (SCUS 97203)

I hope to contribute!