We've been married 15 years. We're our own best friends. We talk & do everything together, but we don't have..?

Tough question, but not unique. You have resentment and anger over the past. You can either (a) forgive him but make him do better or (b) move on. I would dress nicer and be more romantic but insist he do the same. If not, then... One of your alternatives is to have an open marriage. Couples counseling might help a lot if you both want it and both want things to be better. If you both grow old gracefully, the love will increase, but the will decrease, but never has to go away.