Following from that Finnish log thingy in Grand Designs, I'd love a central space, double-height, with room for all the family's activities. So, big table for games, piano, PC, ample storage for ds' "stuff", good northern light for dh to faff about with his models and me with my knitting.
Cupboard for suitcases is a MUST.
Laundry room with lovely warm air for drying indoors in Winter also good.
large utility room with washer, dryer and lots of hanging space
huge kitchen/dining/family space
formal dining room
adults only sitting room
at least six bedrooms - with balconies
at least 4 bathrooms
huge garden with swimming pool, play area, wild space and formal walled garden and kitchen garden
it would all be designed and built to the highest green/eco standards, but would also have warmth and character - constructed using local natural materials
there would be lots of glass used to get the maximum possible light
it would have fantastic sea views and be no more than 10 mins walk to a clean sandy beach
it would be close to a discontinuity in the time/space continuum so that you could be in central london in 10mins
Oh - also - there has to be laundry chutes from each floor going straight down to the laundry room. Everyone just chucks their dirty clothes down the chute rather than in the laundry basket. Saw that on an American housey program and really liked it