Dunno about Good roadblocks, but the worst certainly are from RSE.
I can understand why they put the Rock Smash stone to block paths, but why that fucking rock respawn every time? The one from Route 111 (north mauville) is one of the dumbest examples of lack of attention in gamedesign that I've seen.
The same goes to the secret bases that are "protected" by the same king of rock, like the ones from route 114, before Meteor Falls.
At least, Kecleon worked as a suitable Road Block Pokémon. Not iconic as Snorlax or Sudowoodo, but it works. Then, they dumped the concept in Gen 4.
