I waited a year to check my plugs; stupid idea. Someone put in some crappy platinum ones. I replaced them with some copper Motorcrafts and she's runnun' better now.
Good Ol' Autolite 25's with a side gap, never failed, and I replace every couple months or so... can't beat a set of plugs for only $10 at the Wal-Mart.
I put Autolite Iridium XPs in my car God knows how long ago and those mofos don't wear out, they seem to maintain their gap forever. Of course, they're also like 8 bucks a plug.