If I had to limit my Canon full frame DSLR kit to only five lenses, they would be:
1. Canon EF 16-35mm f/4L IS USM Lens
This lens has many uses, but I do a lot of landscape photography and regard this as the ultimate wide angle landscape lens. The angle of view this lens makes available ranges from ultra-wide through only modestly wide and it delivers very sharp (corner-to-corner) images that make me smile every time I view them.
2. Canon EF 24-70mm f/4L IS USM Lens
The 24-70mm focal length range is my most-used and having a general purpose lens in my kit is important to me. There are some other good choices for this lens, including the 24-70 f/2.8L II and the 24-105 f/4L. If I had only 5 lenses in my kit, I would want my general purpose lens to have IS and the 24-70 f/4L IS has the most-recent/most advanced IS system at this time. This lens has a much higher maximum magnification spec (for macro capabilities) and less distortion at 24mm than the 24-105 L IS (which has a longer focal length range to its advantage). I can't do justice to a list of uses for this lens.
3. Canon EF 70-200mm f/2.8L IS II USM Lens
The 70-200 f/2.8L IS II gets my easy choice for a medium telephoto zoom lens. It delivers very impressive image quality even at a wide open f/2.8 aperture with the capability to create a strong background blur. This lens excels at sports action and portrait photography. It is highly popular with photojournalists and wedding photographers. Landscape photography is another great use for this lens.
4. Canon EF 200-400mm f/4L IS USM Lens
I love wildlife photography and there is no better general purpose wildlife lens than this one. This focal length range, moderately wide aperture and fast AF qualifies this lens for professional-grade sports photography. This is not a small, light or inexpensive lens, but ... I didn't set a budget limit for my "5 Lens Kit". :)
5. Canon EF 100mm f/2.8L IS USM Macro Lens
I also love macro photography, for which interesting and colorful subjects abound. Macro subjects are readily available around the house, at the flower shop, outside ... there is never a lack of something to photograph with a macro lens in the kit. The Canon 100 L has very impressive image quality and the hybrid IS feature makes this lens easier to use and especially easier to frame at high magnification subject distances.
And then I would start saving to add the lenses I'd still feel lost without. :)
The above-listed lenses are my choices for use on a full-frame DSLR. For an APS-C DSLR model, I would swap #1 for the Canon EF-S 10-18mm f/4.5-5.6 IS STM Lens and #2 for the Canon EF-S 17-55mm f/2.8 IS USM Lens.
What are your most important "5"?