I am not really sure if it is my favourite gardening tool as I have a few. But was harvesting some Mandarins and lemons on the weekend and just remembered why I like my telescoping pruner so much - not just for pruning (but it is great for that as well.) I noticed the current models are a little different but still very much the same. Mine is about 8 or 9 years old but still works a treat.
https://www.bunnings.com.au/cyclone-3-25m-quickpull-telescopic-tree-pruning-saw_p0067498 )


PS- declare an interest - I work at Bunnings, but I do love this tool.
Wonder what everybody else's favourite gardening tool is?