Some great points so far on this list:
(this is coming from a custom cabinetmaker, so take with a grain of salt)
Appliances: SubZ ref/freeze, Wolf cooking, Miele DW (you are buying high quality, yes, twice the cost, but refs these days are made to last 5-7 years, same for DW's. These appliances will likely go 20+ years.)
As someone said, undercabinet receptacles. A bit more money, but worth it.
Pullouts in all base cabinets. (I retrofit people's kitchens with these regularly as people age.)
Don't do anything 'trendy' in your kitchen, changing a kitchen to almost any degree in 5 or so years is $$$.
Custom cabinetry...finding a good cabinetmaker, maybe a 3-5 man shop, can be competitive price-wise to some of your better 'stock' cabinet companies. They are local and can attend to problems down the road or if any mistakes are made while the build is going on. DO NOT let your architect design your kitchen layout, only a few rare architects can do this well. Have a true kitchen designer (or equally qualified) lay it out. (This goes out the window if your kitchen is fairly basic and the layout almost lays itself out.) Don't do a two-level island. Don't put cabinets on angles. One sink well placed is usually adequate, but make it big. Not a fan of pot-fillers above cook top (how often are you filling a pot with enough water you can't lift it? You still have to empty it....)
Good faucets. I never want to change one out after it is installed. Rohl makes a great product, lifetime warranty.
Hot water circulating pump. You will have hot water at any faucet in a few seconds.
