In addition to the pot filler....
1. Pasta sink next to range/cooktop. Very cool, saves you (or the missus) from carrying a heavy pot to the sink. If no room, you can gt a specialty pasta pot but it doesn't have as much wow factor.
2. Water softener (ion exchange, using NaCl or KCl, not the scam ones) to keep everything cleaner, except use hard water for irrigation and hose bibs that service the garden. I also like hard water to the icemaker/cold water dispenser because I prefer the taste of water with the minerals in it.
3. Put one soft water hose bib in the driveway for car washing - no water spots.
4. Instant hot water.... I prefer an mini tank under the sink (I use a Bosch/Ariston - works great - just change the anode every year) over a recirculating system. If you go with recirc, though, think about the setup that doesn't mix hot and cold water (i.e., has a separate return line). Hot water tanks have higher bacteria content - do you want that in your cold (drinking) water?
5. Wall mounted lav faucets. Much easier to keep clean.
6. Even if you decide against the bidet seat for now... put it the electrical outlet "just in case".
7. Humidity-sensing bathroom vent fan - with low "sone" rating. I wired the nightlight option in mine to a photocell instead of a switch so that the night light comes on automatically. Also, for $5 you can use an LED bulb in place of the four watt nightlight bulbs that always burn out.
8. Not plumbing, but put electrical outlets in the medicine cabinet for your electric toothbrush charger, etc. That way you don't see the cord clutter on the vanity counter.
9. Stainless restaurant kitchen type prep sink in the garage, if you work in there. Use a foot or knee operated faucet. Also useful in the laundry room or mud room.
10. If your kitchen design is one of those styles that looks like a commercial restaurant kitchen, consider a foot faucet in there, too.
11. I like a counter-mounted air switch for the disposal instead of the typical wall mounted light switch.
12. If you have a pool or spa, an outside shower with a some sort of instant hot water service.
13. An outdoor sink as part of the grill/outdoor kitchen installation.
14. Run the grill off of natural gas... no refilling the propane tank.
15. Drip irrigation on its own timer zone - or more than one if your garden requires it - in addition to the lawn sprinklers.
16. Plumb the rain gutter downspouts to run underground out to the street... away from the foundation.