Actually, it's whatever breed that best fits your lifestyle. I've had wolves, wolf hybrids & Alaskan Malamutes all my life. All are very active and need to be mentally challenged. I've also owned English Bulldogs, Pomeranians mutts and a Maltese (my service dog - VERY smart!), all of which are just content watching TV with you. You certainly wouldn't want an English Bulldog as a jogging buddy, or leave an Alaskan Malamute cooped up all day. Figure out what type of lifestyle you have, then go to
I've also trained dogs for more years than I can remember, am a vet tech and volunteer at shelters in town and can tell you that there's nothing sadder than a missmatch between dog & owner. These are usually the dogs that end up at shelters. So take your time and make the right choice. And don't forget that there are great dogs in shelters waiting for a second chance.
It's a matter of preference. I've had Pitbulls all my life and I would never have any other breed. You have to think of the things you like to do, how active you are and what do you except from your dog. Companionship, protection??