Since you've never tried any oolongs before, you might give the jade oolongs a chance. Even though you prefer darker teas right now, the greener ones are probably unlike anything you've had before. Try a Tung Ting or other Taiwan high-mountain oolong. Wuyi oolongs are also very very good; you might try Shui Xian, Lao Cong Shui Xian, or Rou Gui. You could also try a Phoenix Dancong.