The most useful DIY cutting tool will be the one suited to your project requirements. It will get the job done quickly, safely and will have features and benefits relevant to your application.
Circular saws make short work of long relatively straight cuts. It is great for cutting timber of varying thickness to length or slicing their width down to size. It is a versatile tool and a general workhorse in any D.I.Y. kit.
Jigsaws are extremely proficient at cutting curves, complex shapes and detailed cutting. Jigsaws are not good for making fast, long, straight cuts as the blades generally have fine teeth.
Multitools are versatile in nature, being able to complete several jobs with one tool. They are ideal for doing plunge cuts into timber, trimming timber in tight spaces, cutting pipes and screws to length, cutting into gyprock and detailed sanding. - MitchellMc
Ryobi is a solid brand to go with for DIY. The brand is something you should decide on now so you stick with that battery system. Whichever way you go, spend that little bit extra each time on the brushless models - better performance and longevity. - ProjectPete
I have found a multi-tool will do most things, not always the best choice but it covers so much. +1 to brushless models. - Brad
I use my circular saw more than my jigsaw, but it depends what you're doing. I use hand saws a lot. The ones with hardened teeth are viciously sharp, and they're cheap. It's often quicker to use that than to plug in a saw and put on ear muffs. Maybe I'd change my mind if I owned a rechargeable saw. If you get one, make sure the teeth have enough set on them that it doesn't jam in the cut. I've got one that does that. - pstq
When I started out doing odd jobs and DIY around the house, I needed some tools, and most of us have "hand me downs" from family members. The number of tools you can get from any hardware store is just staggering, and there is a tool for nearly every job. I wanted to share what I have in my tool bag as a beginner or novice DIY and help anyone who wants to get started. Here are some of my essential items for your tool bag:
Regarding the budget or how much you should spend, it's a personal choice, and most of my tools are at the budget end, such as screwdrivers, mallets, etc. But for the power tools, I do like Bosch (again, personal choice). - Nham
The tape measure is one of the most indispensable tools you've got to have in your tool bag. My first hand-me-down tool was a folding ruler that I still have in my toolbox. - EricL
Bunnings Workshop community members should also find these guides by @Peggers very useful: