Wire zapping manifold shield

I was hearing this noise but didn't sound like it was near the distributor and the engine would have faint hiccups. Found that the spark was jumping the wire to the manifold shield causing a miss every now and then. Looks like it has been happening for a while because the metal was eaten away where the spark was hitting.

What have you guys done to prevent this? I'm sure it could use a new set of wires. Before I jump on MSDs, are there any other brands that you guys prefer that are better insulated OR should I simply get some kind of insulating sleeves near the base of the wires? I believe those are more for heat though.

Thanks