oil with sparkplugs

hey guys another question i just went to change my sparkplugs, and i pulled the whole assembly off of the first one, and there was a lot of oil in there i have read that a lot of early LS's do this (this one is a 2000) but what do i do to correct the problem? do i just tighten down the plug and hope it doesn't do it again or what?
Thanks for your advice
Steve

Either poorly seated rings or the spark plug gaskets on the valve covers are bad. Tightening the spark plug wont do anything. If its that loose to begin with, your gonna major driveability issues since your losing compression.

i had this problem had to replace the o ring gaskets on the valve covers if you do them do both sides