5-smeargle 4-Hippopotas 8-Croagunk
http://www.serebii.net/blackwhite/swarms.shtml
Someone else already asked a question similar to this but...
Route 5- Smeargle
Route 4- Hippopotas
Route 8- Croagunk
This is the similar question I was talking about:
http://pokemondb.net/pokebase/81178/how-long-swarms-last-what-pokemon-appear-for-what-routes-swarm
This person asked for all Pokemon so you won't need to look for / ask for answers again.