More storage than you think you could possibly need. All storage under waist-level to be drawers.
Counter space next to fridge.
Counter space next to oven.
Counter space next to sink.
Combi microwave and oven, plus separate oven
Sympathetic lighting: you don't want totally white light (glare off glossy countertops or units if you're having gloss), neither do you want too warm (shadows and dark corners).
Wipe down splashback rather than tiles with lots of grouting - especially above the stove/hob.
Very strong ventilation/extractor fan if you fry a lot, cook a lot of fish or make curries.
A door that can seal in smells but also be left open enough for open plan-ish living.
Seamless countertops, ideally.
Waste disposal - insinkerator if possible.
If you bake a lot, double depth countertop somewhere - either an island (pet hate of mine but some people love them), or at the end of a run ideally next to the oven.