Simtractor is farming game from quite abit ago now (website:
Simtractor.com)
It's got good physics but the graphics aren't the best but you get used to them although you think it's from the '90s.
I recommend V3.5 with machinery addons I and maybe II because you have multiplayer and a nicer farm and map.
I also recommend these mods and skins for it from here:
SimTractor mods and skins (NB some files are for the V4 of the game, like the trailer - I can supply V3 compatible ones.)
Another point is that you can no longer join the Forum as far as I am aware so post here!:
Post tips and questions and anything else for that matter!
-Bvcx3