Typically Normal types are the best since their only weakness is fighting types, which are extremely uncommon (only one I know of is Poliwag/wrath).
Your Vaporeon is also really good but it's rated below Snorlax since it's water type and their are many strong grass/electric counters.
Personally, I have the most trouble against Snorlax and none of his moves are necessarily bad.
I would go with Snorlax, then Vaporeon.