Dogs are okay, but you have to take them out, play with them, walk them, keep them from chewing on everything, and they bark a lot.
Cats on the other hand, just sit around and let you pet them, you never have to take them out as long as you clean the litter box occasionally and you don't have to give any other special consideration to them besides food and water.
---------- Post added 2013-05-27 at 07:22 PM ----------
I don't really like the numbers 5, 6, or 7, so it'd have to be 4 or 8, and I think 8 is too high, so 4 it is.