Unsatisfactory how? Why not just do what you consider to have value? Go for "+EV" in your life. If raping/killing/stealing will have good consequences for you, go for it.

Keep in mind that emotional consequences are very real, too. Even if doing "bad things" would result in some nominal gain, the feelings of guilt or shame may not be worth it. Reputation and risk of getting caught are also worth considering. But I don't think many "immoral" acts are wise or rational in the first place.

Another thing to consider are your standards of value and success. What are your goals? Objectively being happy is no better than being miserable, but I assume you have an ingrained preference for being happy. You may also have an ingrained preference for helping others to be happy rather than causing them to suffer. You may have a natural or conditioned desire to see yourself as a "good person." There are many reasons to act ethically that have nothing to do with a higher power or with notions of "free will."

Your choices may be predetermined, but that doesn't make them insignificant. The choices you make determine the entire course of your life. In a world with free will, you might be able to "change your ways" at some later date and recover, but in a causal universe there is no escaping the effects of what you do. So the idea of determinism hardly diminishes the significance of your immediate actions.