I always get crispy wings when I bake them in the oven.
Preheat the oven to 425 F. Grease a rack* or spray it with cooking spray and place on a baking sheet. Place patted dry and salted wings** fattiest side up on the rack and bake until cooked through and the skin feels crispy. It normally takes about 45-50 minutes...more if they're big, meaty wings and less if they're anorexic wings. I sometimes turn the heat up to 450 F for the last 10-15 minutes of cooking.
Sauce as desired. I tend to sauce as I'm eating in order to keep the skin perfectly crispy.
*The rack allows the grease to drop to the lower pan which encourages crispier skin.
**The wings have to be fresh or completely defrosted and patted dry otherwise they don't get crispy.