Dogs with shorter muzzles generally dont look good in profile shots and #3 seems that the focal point is a little off?
My fav 2 are #1 and #4, #1 for the tight crop and how the eyes draw you in and #4 because it captures that 'moment' better. #5 seems like a pretty standard portrait shot but its still nice too.
In general when shooting small dogs you either shoot form thier eye level or slightly above them while in big dogs its eye level or lower. Of course these are just guidleines that can be broken