I think Capstan Blue Flake is the sweetest virginia blend I have had. Orlik Golden Sliced is sweet as well, but very citrusy. Royal Yacht is sweet, but I think it's the topping, that is sweet.
I'm going to second Wessex Dark Flake. I received some with a few years on it, was expecting some tangy/grassy Virginia, but was sweet as can be. Not sure I loved it like the hype said I should, but definitely liked it!
Chief Catoonah Bailey's Reserve (had a bit of Perique) for me. Wonderful tobacco flavor - and amazing room note. Dick Silverman said it was not cased w/ anything. Have not smoked it in a few years because it's no longer available and I wanted to let it age.