You can CPU mine most any coin, just join a pool that has variable difficulty (Check coinwarz as mentioned for "most profitable"). You will most likely spend more in electricity than the mined coins are worth, but you can still do it.
CPU mining is a good learning tool and stepping stone, but depending on your goals, CPU mining alone will probably solidify your position as a skeptic.
If you want to give mining a better chance, buy a used mid-range GPU and play around with that. You can always sell the GPU if you grow tired of it and won't be out much.
Best of luck...