My suggestion would be start looking into drinking loose leaf tea as there will often be a more full-bodied flavour to it. I second DavidsTea as I go there about once a week to get new teas. My current favourite is Red Velvet Cake tea. It's fabulous! Their herbal teas are wonderful as well.
Most herbal tea will often be slightly sweeter than a black tea b/c it won't have the tannin-bitterness often associated with black teas. Oolong is a fermented tea and can have a lovely musty sweetness to it. The flavour does take some getting used to though.