On a non-daily driver the aluminized will last virtually forever. The Stainless however will look better for longer. Regular steel exhaust should be left to early 80's Toyotas and such. There is very little price difference these days between aluminized and plain steel.
Jay is right. Aluminized is the most cost effective way to go. The factories used the stuff and it is not uncommon to see 30+-year-old original pipes (but rarely mufflers) on old cars. IMHO, you should NEVER use plain mild steel. It begins to rust immediately. Stainless is indestructible but also expensive and tough to bend.
Like mrgem said, it's rare to see the original mufflers... not due to rust though. Due to the insides blowing/burning/falling out giving you that nice cherry bomb rattle and hum /forums/images/icons/wink.gif