Here are some of tested and suggested mods for Kingpin. If you have more that you'd like to share here is the exact place.
Note. It is better to test each mod with gog installer first before you add new one to this topic.
1. Capture the Bag (multiplayer)
Kingpin's idea for a CTF mod with a few changes to weapons. Each team has got 500 bucks in their safe. Each time the enemy uses your safe, they take one of your Ben Franklins and will try to get it back to their base. I bet you figured out the rest.
http://files.filefront.com/Capture+The+Bag+v10+Final+Version/;4269;/fileinfo.html
2. Last Man Standing (multiplayer)
A mod implementing Last Man Standing rules we all know and love. You start with a few points, if you die you lose one and must wait until there's only one player left. If you go down to zero points you get dropped to spectator and fail. 'Nuff said.
http://files.filefront.com/LAST+MAN+STANDING+MOD+FOR+KINGPIN/;13530;/fileinfo.html
3. Godfather 1.6 (multiplayer)
You start out as a raw recruit and go up the ranks as you gain experience by killing others. Higher ranks give you more health and better guns after respawn.
http://files.filefront.com/Godfather+16/;16131;/fileinfo.html