Some video games:
AK-47, Walther PPK, FN P90, Ruger Super Redhawk, Vz.51 - Goldeneye 007
H&K MP5 - Rainbow Six Series
AI AW and Convert - 007 Nightfire
M4A1, M249 - Delta Force series
Barrett M82 - Rainbow Six 3...it got banned from the expansion pack because it dominated the game on online multiplayer
M4, M16, RPK-74, OICW - Ghost Recon I and II
Taurus Raging Bull, Tavor, FN SCAR, HK MP7, SIG 552 Commando, Desert Eagle, HK G36C, PSG1, etc - Rainbow Six Vegas, basically gun porn
Everything imaginable - Ghost Recon Advanced Warrior I and II....seriously, I've never seen so many real-to-life guns in a video game, its incredible
Mk.23 SOCOM - Metal Gear Solid
Mossberg 590, M60, USAS-12, AK-74 - Soldier of Fortune II
MP5...with grenade launcher - Half-Life
AI AW, G3/SG1, FN P90, Beretta 92FS, Desert Eagle, Steyr TMP, AUG, SIG550, HK USP - Counter-Strike, classic gun game