What's the best Lawnmower?

Great question. Short story long, it really depends on your use case. For example; If you only have to mow a small front yard you probably don't need a zero turn mower with commercial grade hydraulic drive motors.. a standard push mower might be the best thing for you. (you also may want a self propelled push mower if you're into that sort of thing)

On the other hand if you have 4 acres to mow, you had best get a zero turn with about a 48" deck or a lawn tractor from a reputable brand. 

What type of grass do you have? some grass is best with a specific mower like zoysa grass with "Reel style" mower being cut about 1 to 2.5 inches

If you have some intensely steep hills to mow don't mess around get a commercial grade rated for that slope... safety first. (I say commercial grade because you want to make sure the drive motors can handle the work load of the hill on a regular basis)

so to sum up, the main things to consider are the following:

Do you have any steep hills that a standard mower might have trouble with?

Do you have special grass that may require a special lawn mower for the best results?

How much yard do you have to cut?

What is the smallest space you have to get into with the mower? (gates or around certain items)

How much are you looking to spend?

Hope that helps someone in making their "Lawn Maintinance Equipment" purchase.