I'm not sure there are any coins that are good for mining with a CPU than there would be with a GPU. As both can run similar processes but GPUs generally can run more complex ones as they have a generally much faster clock speed and also quite a lot of RAM normally. Unless you could find a new altcoin that has just started to be mined so there is a low difficulty then you might get something. Otherwise, without an asic/GPU, mining isn't economically viable.