It's a pretty hard question that, as it really depends on what you want to do with it. Fun around the farm, touring, practical, robust etc.... I've flown many types and still haven't really settled on an all rounder favourite yet. Other than maybe the C206... but that's not RAA!
One of the aircraft I was most impressed by would have to the the Rans S7 Courier, here's a quick video I did of a flight in one.
However I do like side by side seating for those times when you're travelling with a good friend etc... so that's the only thing that's holding me back from saying it's one of my 'most' favourite aircraft! But definitely one of my favourites.