i always attack ev train between lilycove and the safari zone. Rt 121 Poochyena Lv 26 Common Shuppet Lv 26-28 Common Mightyena Lv 26-28 Common Oddish Lv 26-28 Uncommon Gloom Lv 28 Rare Wingull Lv 26-28 Uncommon Kecleon Lv 25 Very Rare
depending on how you ev train, this might not work for you if you don't pay attention to what you're battling. you need to avoid the oddish/gloom/wingull/kecleon but you won't see them often. the mightyena gives 2 attack evs instead of the 1 from shuppet/poocheyena so you'll have to adjust for that as well. because you'll be fighting a good deal of mightyena's though, this is the fastest way to attack ev train imo.
"One does not sell the earth upon which the people walk." -- Crazy Horse