I think Liffey Falls would be my favourite waterfall in Tasmania. Not only is it a beautiful waterfall, but you're not stuck behind a fence to view it. You could get right down there and sit on the rocks and enjoy the scenery. A beautiful spot!!
This walk we did was to the Alum Cliffs. It was a stunning outlook.
We had camped the night at Deloraine and were able to leave our van there while we went to Liffey Falls and Alum Cliffs. Deloraine is a gorgeous little town.