Given the issues with modern furnaces (reliability, longevity, etc), you might want to wait until you HAVE to replace your trust old furnace.

Thank you so much,...another LONG winter ahead and couldn't decide.

Are there any long lasting heat exchangers,..stainless steel or other non corroding materials?

Which brand would you most trust??

In my opinion bad installations are the cause of the majority of cracked heat exchangers. Furnaces which run too hot and short cycle will cause the heat exchanger to die a premature death.

The other problem is in order to win the high efficiency race, manufacturers are using materials which have high rates of heat transfer. It is great for efficiency but not necessarily good for longevity.

I would trust Carrier/Bryant, and Trane/American Standard. Buy a furnace that has a lifetime heat exchanger warranty. Find a contractor who will do a good installation.

Thank you Mike!
These brands have more unsatisfied consumers,..see link.
Olsen has top rating.

Here is a link that might be useful: Consumer Reviews of AMANA furnaces

Don't take ANY stock in those ratings. What they should be rating are the installers. Most problems arise from the installation, followed by neglect of the homeowner of a new system.
Furthermore, most people are more apt to post a commentary / review when they are dissatisfied.

As the other poster said - Carrier or Trane, or their sisters Bryant and American Standard.

Thought I do a update...put in a Trane in fall 2016, running good, just had it inspected from the installer the first time ...all seemed good but I haven't got the inspection done yearly as supposed to, which seems to me a money making proposition @ $150 a shot. I might take a gamble and loose warranty. Asked wife since she's paying the gas bills if we're actually saving money, answer..not much different. The old larger furnace with larger blower heated the house in no time, this one runs forever in cold days to bring it up to temp. in mornings. I've told this to the installer, he said that's fine, no harm done.

The furnace should have at least a 10 parts warranty. Read to Trane warranty and see what it says about yearly maintenance inspections. Every other year for a new furnace should be sufficient as long as you keep the filters clean.

If the installer is giving you a labor warranty, then the $150 per year is to subsidize any labor charges in the future. You have to decide whether that is worth it or not.

How much do you set back the temperature and how long does it take to recover on a cold day?