I also like the Weapon Select option as it allows me to have a shotgun at all times, whenever I have run out of ammo I select it and have 6 shots 
So far I like the 9mm pistol/shotgun combo the most, 9mm for far away, headshot and if not pump two more shots into the body for a kill and the shotgun for close up action.

So far I like the 9mm pistol/shotgun combo the most, 9mm for far away, headshot and if not pump two more shots into the body for a kill and the shotgun for close up action.