Ennerdale.
Then Frog Morton's Cellar.
But for a regular Aromatic, really I think just about anything from Sutliff is probably going to be fine. Out of the four or five blends I've tried from them (Vanilla Custard, Frosty Mint, Top Shelf, Chocolate Truffle, Molto Dolce) they're all reasonably saturated and burn very well. They must be putting accelerants on these blends because goopy Aromatics are the only things that I've ever seen smoke themselves just sitting on the table after you light it. It's not hard to get them burning too hot.
As far as specific Sutliff blends go, I think the flavour of Z92 Vanilla Custard translates through the smoke particularly well.
I should note that sometimes a small bulk sample is not going to be a very good representation of an Aromatic. I know that bulk Ennerdale isn't half as potent as a fresh tin, and I think the same will generally go for most other aromatics.
With Sutliff blends sometimes buying 8oz of bulk is pretty good though.