The answer is:
“Only the ones that future buyers will also want and be willing to pay for.”
As a general rule, choosing the functional over the merely cosmetic and choosing neutral over unusual or exotic will pay at resale. Taste and current trends can also affect the value of an update. Unusual colors have a limited appeal.
Updates that increase usable space (an extra bathroom, larger and/or upgraded kitchen, master bedroom suite, more closet space, conversion of unused space to a home office).
Updates that will lighten and brighten your rooms (white or light color paint and floor coverings, light woods, skylights, larger windows, French doors).
Updates that will open your home to the outdoors for fresh air and entertaining (French doors to the patio or garden).
Updates that will increase privacy and security (fencing, landscaping).