I would without a doubt, have to say the APBT
My male is a Full American Pitbull and my female (the Brindle) is a APBT/Staffordsire mix,...I have had Shepards and a Rottweiler,...but these pitbulls have stolen my heart!.They are smart a s hell, have a good disposition (gotta pay attention to bloodlines), are very easy to train,..and eager as hell to please! My female Roxy is THE most loyal dog I have ever owned. My male (fawn and white) is a loyal dog,..but sometimes he tries to pull rank and think he owns the joint!!..hahah,...but he KNOWS who the real Alpha is around here and a raised voice will set him straight! I have never had a problem with people agression,...but boy do they like to go after other animals!!(other dogs,rabbits,squirrels,...you name it!....they are great together because I got them both as puppies. Best dogs I have ever had overall!