For once or twice a year use around the yard, you'll be fine with just about any saw. McCulloch, Craftsman, Echo, Poulan, etc. will last for a long, long time with proper maintenance. Top brands like Stihl or Husky are serious overkill for your intended use.
I would suggest saving money and picking up a lightly used saw off craigslist. Lots of people run to Sears or HD and buy a new saw to clear one big branch that comes down in a storm. They use it once and then let it sit in the garage for a few years before realizing they don't need it. I've picked up many pieces of power equipment this way.