WoS Gold Label and Grand Cairo used to be very satisfying in terms of nicotine delivery. They were most potent Wilsons snuffs (among all their types). Jaxons SP Premium wasn’t bad. But I’m not sure if they still are made from the same tobaccos, and if you find them of rather disappointing strength, don’t blame me mentioning them.
To mention some less potent ones – GH SP, J.&H. Wilson SP No.1, WoS Best SP, Tom Buck, SP 100, Toque Original. More or less nice snuffs, but rather underwhelming in nicotine department.
Some would probably chime in recommending Toque SP Extra. I have only tried the plain base of this snuff - Toque Quit. It is noticeably stronger than Toque Original, but I found its widely boasted potency somewhat overrated. The only truly strong Toque’s snuff is USA Whiskey & Honey. Also, it’s the consensus of opinion that this snuff is head and shoulders above the rest Toque snuffs, when it comes to potency (but it’s a high dried type, i. e. fine and dry snuff, not an SP).