Lunar, you are one with skill in tact. Use it. Tell your brother exactly what you told us. Reworded, of course. I bet he might appreciate it.
Find the right moment and confront him with how you feel. I agree with WizardofOdd, you have to get it through to him and if he doesn't want to listen you have to be a little more forceful and not only for your own sake. If he is all the good things you say about him he should be able to get the message sooner or later.