Ethernet over copper will be "good enough" for the next decade minimum, and probably two decades.
Wireless still needs APs to plug in.
Put cat6 to places where you'd mount an access point, so center of ceiling. Run at least 4, maybe more to the back of your "tv area" and one to where ever you might put surround speakers.
Wire ALL your twisted pair back to one patching panel. For cost reasons this is often fairly central in the floor-plan. You might end up with one patch panel per floor, or details might make it impossible to have just one panel. Do put tie cables between patch panels, if you have more than one.
If your ISP is cable-based, they probably won't use any wiring you supply. Same goes for Fibre-based internet service. The best you can do there is make sure there's some way to install those services, which means conduit, large radius bends, and possibly draw wires.
ADSL/VDSL/ISDN based services are a bit different - they'll run quite happily over your ethernet wiring, but won't be Ethernet. Its not uncommon to use the center pair to carry phone-cable data over twisted pair to your router. As a bonus, you can relocate your router around the house by repatching. Neat AND tidy.
RF / aerials
Do you have a satellite dish or external FM radio antenna ? That's another thing that can't be carried over twisted pair copper.
Power can be sent over ethernet, but you're limited to about 18 Watts. That's enough for a camera, or an AP, but you're not going to run a computer off 18 watts.
So put in enough power sockets that you could do away with multiboxes / multiboards totally.
In your desk area, consider the wall plates that contain USB charging sockets too - they're cheap and if they go out of flavour can be swapped for the next big thing in a decade.