I'm a total sucker for any kind of purple makeup. This primer is by Korean brand It'sSkin, and it also comes in a green format to cancel redness in the skin.
This lavender primer is what I use on a particularly crappy day (i.e. if I hardly slept and it's gloomy out). It has a nice, light scent and feels very moisturizing. The colour lavender has a great brightening effect to the skin, offering a subtle but instant pick-me-up. I don't use this all over my face - I'd look like a ghost. Instead, I like to apply 3 small dots on my cheeks, and maybe one dot on both the forehead and chin, and then pat it in. Then, continue on with the makeup as usual.
As you can see, it blends out quite sheer but still gives a nice brightening effect. This primer's primary function is simply to brighten the skin; I don't think it does much in the application or longevity of makeup. Perhaps you can layer it over another primer you usually use! Unfortunately, this wouldn't work on darker complexions - Korean makeup is pretty much centred around light complexion.
This option is budget friendly, but a good higher-end option is the Stila Colour Correcting Primer. It has a swirl of different colour-correcting colours such as green, lavender and apricot, but overall it brightens the skin really well.