There are not many plants that I try to get rid off, but we have 3 main "enemies" here, which we try to keep away from our stable, riding tracks and around our meadows. It's not easy, but we already can see success after displanting regularly. Those plants are the dooryard dock, the Nootka lupin and cow parsley and all three of them are really invasive. 
So after our very nice evening ride, we started another round of cutting and pulling up weeds. First around the stable and then we went down to the riding track and kept going there. It's amazing how huge roots the dooryard dock gets, really difficult to pull them out. Well, I think we did quite a good job and came home around midnight tired, but content.