Well, for starters... what size lawn do you have? What are you using to mow it currently, and what features/size/power factors do you like/dislike about your current mower? How much is your budget? Are you fixed on new or used, or flexible?
My original post had a link to my requirements, but I'll post them here to make it easier. Budget is ~$4k. For that amount, given my requirements, I'm looking to buy something used.
My last tractor was a Craftsman GT5000 which performed well but died prematurely. Interim tractor was a big-box Husq that wasn't nearly up to the task.
I have 1.75 acres. One acre is turf lawn (euphemism for "mostly dirt"). This is twisty-turny around trees, kids and other landscaping obstacles. There are surface roots that occasionally require raising the deck a bit.
The other .75 acre is field converted to lawn - it's thick, dense and grows fast. It is more-or-less straight runs, but it's a bear to mow. Mid-season, I generally have to mow weekly. If I let it go, I'm hatin' life and kicking the dog. It needs a minimum 54" deck and enough power to throw some grass.
I have numerous opportunities for ground-contact - tilling, plowing, aerating, etc.. I say "opportunities" because I lack attachments.
What I do have is a dumper cart, and I use that a LOT. Hauling yard debris, dirt, stone, concrete, construction materials, etc...
With all the stone and dirt I move, I'd LOVE to have something that could load or push, but the better half of this operation (trust me, I'm being kind) doesn't want to spend that sort of money.