It's not simply a matter of who has the greatest feats, as no where would that factor that Vader is weak to force lightning. Vader goes down to Snoke's force lightning and
It all rests upon how close Maul and Vader can get. If they can't get close Snoke does his 'force lightning coming upwards from the ground trick' on Vader so that Vader can't block it and gets fried and proceeds to do something like the above on Maul.
I'm not saying Snoke solos, I'm saying that Snoke could solo. (a seemingly unavoidable force lightning)
Vader took punishment from Palpatine's lightning and his suit absorbs shocks (Palpatine is an exception because he's that powerful). Snoke isn't stomping Vader unless he has shown he can mass-spam lightning like Palpatine, as which we only saw him shot once through his fingertips. The one in bold is speculation at finest, so you can't automatically attribute Palpatine's feats to Snoke's. I haven't seen him pull down a freighter or do anything near Palpatine's level of skill. We can assume, but it can't be proven by official sources.
Force lightning is blockable from the ground. Otherwise, Mace would be fried the moment Palpatine shot lightning up at him. Of course, you can argue it will "spread" to Vader's systems through conductivity, and even so, it grants him enough time (similiar to the Emperor's) to get into melee or simply use the AT-AT feat above. Weaker opponents like Savage Opress have resisted Dooku's lightning (which can do more damage to Nightsisters than Snoke's does to Kylo Ren) and Maul is above him. Both are enchanted by Mother Talzin to suggest their augmentation. Maul is more resilient to lightning than Vader, and his ability to pull down a freighter single handed while running away from pirates supersedes that Rey and Ren did for a while.