4 & 6 don't do much for me, but I really like all the rest of them, the first especially. #4 just seems rather dark and indecipherable. . .i.e. I'm not really sure what I'm looking at. #6, while a nice portrait, seems a bit plain.
Nice informal portraits, Juano. Especially #1, 2 and 3. The last one's not bad but not quite in the same class as the first three. You could have left 4 and 5 out of your posting without losing anything.