Things I appreciate in mine
Wifi
Plenty electric sockets
Workbench with kitchen cupboards above as storage
Led strip lighting
Air compressor – mine is twin outlet so retractable cable reel at door for car tyre pressures, other outlet at bench. Air gun very useful for blowing crap out of cassettes etc
Beer fridge
Good stereo
TV
Burglar alarm
Foam matting on floor
Pegboard behind workbench
Bench grinder- grinder and a wire brush wheel
Good quality vice
What I would really like is a sink and running water. Thought an old Belfast sink with garden tap above would be ideal