Well, I had a cat called Green once and he was awesome, i swear he understood nearly everthing i told him which was cool, he used to do random things like bring me presents (ussually bits of food, dead birds or random items) and he used to follow me to school and where ever i sleep he used to sleep next to me and sometimes he used to attack people who try to wake me up lol. He was struck by lightening and died.
I've also had two dogs (Tyson and Niko), two hamsters (Nibbles and Hazel) and a Terrapin. The dogs were friendly but i wouldnt call them friends, The Terrapin was okay and The hamsters were good and other cats i've been with are quite boring and lazy so I dont think either are good.
For me It's gotta be Wolves because a relative of mine has to many to look after and i help him from time to time, Wolves are by far the best animals ive been with.