If I wrote all the tools I use around here I would get writers cramp
A good wheelbarrow
T Post Driver
T Post Puller
Every kind of fastener you can imagine (Nails, wood screws, metal screws/washers/nuts, staples, etc.)
A come-along or 2
A mile of nylon string 100# test or better (White and Odd neon colors are easier to see.)
"Most importantly, have some tools that you have no idea what it is or what it's for - you'll need it one day."