Who's That Girl is a 1987 romantic comedy starring with Madonna as Nikki Finn and Griffin Dunne as Louden Trott.
The following firearms can be seen in Who's That Girl:
Colt Lawman MK III Snubnose
A motorcycle cop is armed with a Colt Lawman MK III Snubnose Revolver.
Colt Lawman Mk III snubnose with rubber grips - .357 magnum
Ruger Security Six
The arms dealer (Sean Sullivan) shows Nikki a Ruger Security Six revolver.
Ruger Security Six with stainless steel finish and 4" barrel .357 Magnum
Steyr AUG A1
The arms dealer (Sean Sullivan) also offers a Steyr AUG A1 assault rifle to Nikki (Madonna).
Steyr AUG carbine with 16" Barrel - 5.56x45mm
The arms dealer (Sean Sullivan) also shows a Maadi ARM mocked up to resemble an AKM.
AKM for comparison - 7.62x39mm
An M16A2 was seen in the arms dealer's merchandise.
The handguard of an M16A2 seen on the right.
Nikki Finn (Madonna) eventually chooses a Beretta 92F to buy from the dealer.