For most people it is a dog because they are very loyal to their masters they are trainable and they are one of the first every to tamed animal they are good for protecting such like police dos and in home they keep you company sometimes they get sad when you feel sad too so that's why a dog is a man's best friend.
Hi this is orlajess513 here and I think everyone is different but I had a guinea pig and they can get heart failure at any age young or old, A rat makes a good pet and can be trained tricks but mine had a respiratory problem, I've got a hamster and she is going on well but then again all most rodents get wet tail which is a type of disease.
Hi this is Georgiarulz.
Dogs are the best if you have spare time and lots of money as they need a lot of love and attention, exercise and space to run around. They also cost a lot as the need to be washed regularly, fed 3 times a day and need a collar and other clothing and accessories.
I have to agree that guinea pigs are the best pet. They come in all different breeds and are soft and calm when in a humans hand. They don't need as much attention as they can amuse themselves with play equipment and don't need to be taken on walks. As they are small they don't use up to half the washing liquid as a dog and only need a small cage and a cup full of food a day. Now all its missing is its owners. :)