1. Canon 50mm 1.8 STM
Generally, when purchasing a new DSLR camera you will get a "kit" lens. This is a general all-purpose lens, typically with a 18-55mm zoom range. Although that is a great lens to start with, you may find yourself looking for more lenses to achieve a certain look, or to enable you to shoot particular subjects.
The Canon 50mm 1.8 STM is a fantastic lens for the money, and it's usually one of the cheapest new lenses you can add to your collection.
Its sharpness is amazing, especially when stopping your aperture down closer to f/8. I'd say sharpness wise, it's on par, if not better than some of the zoom L lenses.
One of the main features is its f/1.8 aperture. This allows you to do a multitude of things that your kit lens simply can't. Having an aperture of f/1.8 allows a lot more light to get into your camera, meaning you can often adjust your ISO lower, to avoid taking grainy images.
Getting blurry background images (bokeh) is a doddle with this lens. Sometimes it's a little too easy, so pay close attention to ensure the object you want is in focus.
The only thing that could be conceived as a downside for this lens is the lack of a zoom. However, that is barely a downside considering its price and performance, and I'd argue that lacking a zoom will allow you get more creative and move more whilst shooting.
2. Canon 55-250mm IS STM
Depending on what you're shooting, you may find yourself possibly needing more reach whilst you're out with your camera.
A telephoto zoom lens will give you the ability to get much closer to your subject if you physically can't.
You will generally need to consider a lens like this for portraits, wildlife and sports. Having a range of 55-250mm is really convenient for myself, as it allows me to get many different kinds of crops and perspectives during portrait photo shoots.
This lens has great sharpness for its price, comparable to the kit lens. STM makes the focusing quiet and accurate and the IS is really handy at keeping the image stable and clear whilst fully zoomed out.
My daughter has recently got into bird watching so I have found myself using this lens a lot more recently!
3. Canon 24mm STM
A personal favourite of mine which I foolishly sold recently, It will be mine again soon!
This is in a similar vein to the 50mm 1.8 STM lens, it's a prime lens so it doesn't zoom.
It is a very sharp lens with a wide angle view, which I generally shoot a lot of. If you find the 50mm is often "too zoomed in", then this could be for you.
One downside of this lens compared to the 50mm is the fact it is f/2.8 so it's not as fast. This is not an issue for me as I generally don't shoot below f/2.8, but this could be a deal breaker for you.
It's also typically a bit more expensive than the 50mm, and this lens can only be used on crop sensor camera bodies so it wouldn't work with the 1D, 5D and 6D range.
I used my lens for portraits and videogaphy, and I found it to be a very handy, sharp lens in situations where I didn't have much space to move about.
4. Canon 10-18mm IS STM
This lens won't be for everyone, but for the price, it allows you to take some high quality, super wide angle shots.
This lens will suit photographers that shoot landscapes, interior and exterior architecture and videographers.
The unique perspective this lens can give you is amazing, it's not too flattering on people but it can be super convenient if you need to fit a lot of space in a single image.
Shooting wider can help keep a steadier shot, but this lens also comes with IS so it is even more stable! This feature is what could make this lens a must for some videographers if you need to keep things steady whilst on the move.
5. Canon 18-55mm 4-5.6 IS STM
Yes, one of the best lenses for beginners, if not the best!
The lens you generally get with your camera, it has a good range to start off with for portraiture, landscapes, products, events, architectural, pet photography and video work.
This lens has good sharpness and even comes with STM for quiet and quick focusing and IS to give you more stable shots.
I believe this lens gets some flack as it will be the first lens people start off with, so its quality gets confused with the ability of an amateur photographer. In the right hands, and after learning the basics of photography, you will find out this lens can be very capable.
I wanted to end this post with this lens just to point out hat it's great having lots of good lenses, but more often than not, you don't need them all. I hope this has helped you decide which lenses may work best for you, and potentially this has helped you save money.