All three of the roasted Dong Ding oolongs I've tried have had that lingering coffee-like rich roasty bitterness — though I'm not a huge coffee drinker, so maybe somebody with more of a taste for coffee would disagree.

There are also coffees (Ethiopian, Kenyan) that when light roasted are especially tea-like and fruity. Not roasty or bitter at all. Like, you'd wonder if it's even coffee if you're only used to the homogenous dark Starbucks stuff.

Try a pu'er -- incredibly dark, rich fermented teas. If you're in SF, Red Blossom Tea Company has a wonderful selection.