The Craftsman DYS4500 is an excellent product that sports an automatic transmission and one pedal that adds to its comfortable ride. It provides an awesome 54" cutting deck and easy to use controls. With extra attachments in the winter it doubles as snow remover and hauler and can also stand up to light to medium yard work.
There are a few sit and ride lawnmowers on the market. Myself, I go for Kabuta kit tractors. For around the price of a normal ride on, you get a high power unit with hundreds of available add-ons. Hope this helps.
The Cub Cadet is the best riding lawn mower I have ever used. It manages uneven ground very well and can really stand up to abuse that occurs over the years. We have a very low lying area that it managed well without bogging down.
I think the John Deere 240 is a very good lawn mower. It is actually 900 dollars but it is a great riding lawn mower. It will cut up the tallest of grass with no effort. I love this mower and I am sure that you will enjoy it too.