Alan and Terry (and recently Ross, too) have been coming to my rescue for five years now. It started when our furnace in our old home had died. We were given a very high efficiency furnace for a great price, and it was installed the next day, in the dead of a ridiculous winter storm.
Then was when our A/C unit stopped working. They just inspected it, topped its coolant back up and saved us from the OTHER weather extreme...
Then we needed a vent built from our washroom to the outdoors, and again, A & T were there.
Since, we've moved to our dream home and the first thing we did was get A & T in here to install a central air unit.
And just yesterday my 23 year old furnace (should've taken my old one with us when we moved) stopped working. It turned out to be a simple fix for the aforementioned $254, but we were given trusted advice to start saving for a furnace, but also told that they'd be there to help us if we can't get through the winter.
A & T. Call them because of their reputation, but keep calling them because they're all nice, honest dudes that truly WANT your business again.
Don't cheap out and just get the cheapest quote... They properly back up their certified work and get the job done right, the first time.