Numbers may be different due to different bonusses in the game.
(This guide is with 11% Mastermind and wheelman)

New York

Street Thug
Auto Theft (ratio 1,3 : 1)

Associate
Bank heist (ratio 2 : 1)

Soldier
Museum break-in or Clip the Irish mob’s local enforcer (ratio 1,5 : 1)

Enforcer
Run illegal poker game (ratio 2,2 : 1) (You need consumables for this)
Federal Reserve Raid (ratio 1,5 : 1)

Hitman
Eterminate a rival family (ratio 1,7 : 1)

Capo
Whack a Rival Crew Leader (ratio 1,7 : 1)

Consigliere
Steal an Arms Shipment ( ratio 1.8 : 1)

Underboss
Order a Hit on a Public Official (ratio 2.0 : 1) (You need consumables for this)
Extort a Corrupt Judge (ratio 2: 1) (You need consumables for this)

Boss
Settle a Beef... Permanently (ratio 2 : 1)


Cuba

El Soldado
Silence a Noisy Neighbor (ratio 1,7 : 1)

El Capitan
Hold Up A Tour Bus (ratio 1,8 : 1)

El Jefe
Offer "Protection" To A Nightclub (ratio 1,8 : 1)

El Patron
Gun Down An Enemy Crew At The Airport (ratio 1,9 : 1)

El Padrino
Supply The FRG With Some Extra Muscle (ratio 2 : 1)
Set Up A High Volume Smuggling Operation (ratio 2 : 1)

El Cacique
Send Some Help Home To New York (ratio 2.03 : 1)