First off you have to ask yourself some questions like how long is the driveway, how much snow will I need to move and how far, is the driveway flat or a steep incline, what are your physical attributes-how big of a machine are you capable of handling?
There are so many brands out there but many are manufactured by the same companies. I would certainly consider a machine that has a history of reliability and also the ability to get parts fairly easy. Keep in mind there are "snowblowers" and "snowthrowers". I prefer a "snowblower". There are single stage and two stage- again my own preference is the two stage. The horsepower is a definite factor as you want to have enough power for those heavy wet snows. Personally, I would not consider anything less than a 6-8 horsepower machine preferrably the 8. Then, the incline issue. I would definitely want a "power driven" machine unless you have a lot of muscle power of your own! There are quite a few varieties but a differential lock allows you to use one or both wheels in power mode. The engine too, has it's features but most of those issues are preference. I like Briggs and Stratton because parts are readily available just about anywhere. I'm not saying the other engines are not as good but may not be as easy to get a part in an emergency. Again, it's preference. Another thing you might observe is the construction of the machine, location of controls, electric start vs manual start etc.
I own a (90's) John Deere TRS32 which is a 10HP snowblower! My reason for choice is that I also own a Scotts lawn tractor which is built by John Deere and parts are readily available all the time in my area (Farming country) I had owned some others like a Simplicity that too me was a total piece of JUNK- maybe they are better made these days as I'm going back into the 70's. I know from other folks that the Ariens, Toro, and Troy-Built are very good machines also. However, what made up my mind was seeing the John Deere in action in a heavy wet snow and watching others struggle with their brands. My John Deere never hesitates! It will walk right through the area at the end of the driveway where the plows pile up 6 feet of snow on you! I don't have to stop and take a little and back-up and all that stuff! 1st gear and away goes the snow!
I'm not an expert but just my own opinion and experiences hopefully will help some folks make a decision. Keep in mind all those Walmart, K-Mart, Sears, Lowes, Home Depots, etc sell you the machine at a slightly lower price but when you need parts--------------that's another story-------especially if it's one of the cheap store brands built by MTD or Murray etc. Better of with a local dealer--------he also knows how to fix them which is a major plus for those of you who haven't a clue!