I have not yet seen Infernal affairs 3, but seen the other 2. I watched Infernal affairs first, i liked it, great acting, the actors showed alot of emotions throughout the film. You connect with the characters more than the departed. The deoarted was not so great, some of the scenes especially the ending made you think what the heck is going on. It seems like they rushed the ending bit. The scene where the detective falls from the building, lacked emotion whereas in Infernal affairs, you felt for the character more.