Spark Plugs

One of my wires was breaking down so i needed to replace the wires. The only company that has the actual set is accel so i got them. I was putting them on and for shits and giggles i pulled the spark plug. It is "OK" on the inside but the outside it nastsy. It was rust and build up. You can;t hardly read the plug numbers. Is this affecting performance or is it just cosmetic? Also, what should i replace them with? Don't say the multi-pronged plugs. They can;t work. Electricity takes the path of least resistance. THanks
P.S. Anyone try the switching of the wires like in a previous thread?

ok, anything outside the combustion chamber, dosnt matter much. unless you get carbon tracking indicating the electricity is grounding outside the cylender to the block. thats bad, but rust and dirt dont make any difference, so long as the part inside the block, and the part covered by the boot look good, youre fine.

now, multiprong sparkplugs, alla splitfire, do work. however not in the way people think. they do not create multiple spark kernals. what happens is an increased area for spark travel, meaning that there are more options for that single spark to travel on, so your plugs wear slower, last longer, and foul less often. as one area becomes burned from spark, it just moves to another area, and so on and so forth, but you are right, it will only travel on the path of least resistance.