The common mantra is that a kitchen improvement and a bathroom renovation will bring the $2 for $1 investment return (or thereabouts). If done properly, a new kitchen can change the entire feel of a property; A new expanded bathroom can take a modest master bedroom and turn it into a four star hotel suite quality experience (at least for a night or two).
There are breakdowns of parts of a kitchen that detail which fixtures bring the most value back in resale. Each is important and ideally you are designing all of it to be cohesive, but if you are just doing some of your kitchen the counters are a must, and the cabinets have to be a close second.
Additionally, (and I take a turn here) I would jump outside the house to say that an improvement to a front porch, a walkway, an exterior entryway, front yard especially, and/or your deck can bring double plus resale value from your investment. It is the first thing your buyer sees and since most people are looking for homes in the light of a beautiful blue Santa Cruz day, they imagine themselves in this new space. It is their new space and the investment to make it appear as such is what drives that impression home. When making the decision to move to Santa Cruz many are thinking of the outdoors, therefore you are validating their decision and marking your home as the place that meets their personal wants and needs. Kudos to you ~ more value to you.