My opinion, Shieldon.
i would say gible or or or ....... sheldon
Well i think the best partner is pachurisu but you can check quests that have piplup, turtwig and chimchar and mime jr and ect, if you go to shadows of almia.com they tell you what the partner list consits of.
Chimchar is the best partner Pokemon
I'd say.... Pachuricu, even though I have about 15 other partner pokemon's (without action replay.) Remember this is my opinion so other people might think something else.
squirtle and pikachu will be the best
Pikachu
there isnt, different element assist work on different pokemon.
This is an opinion question. I think that Pachirisu is.
Starly is a pretty good one, you will get there with him/her!
Riolu, Phanpy or vulpix
Totodile, with partner of Torchic
Any Pokemon can be OK. I have a Umbreon on XD, and it's the best Pokemon I have in the whole game. On HG, My Latias can survie almost anything( but that might be because it's a dragon type...) I also have a Maginiam, and he is my best partner I got. On ruby, my Spectile is almost unbeatable, and a good partner. So, the best answer is ANY Pokemon would fit for this answer, even the weakest Pokemon would. Never judge a book by it's cover. In Pokemon, never judge a Pokemon by their weakness.