tldr: best single thing we chose: giant stainless steel sink .
A giant sink. I think someone else said this up thread. But, then, someone else said 'small sink'.
Having lived with many kitchens over many years, some designed by us, some not, we learned from our experience and decided, yes, we need two sinks, but also, one of them must be big enough to fit oven trays (and to fit a standard-size frying pan horizontally (including handle)). (The second sink is relatively small, does its job OK.)
That was a few years/decades ago; we decided we were right. Other things we could do without (OK, perhaps not the dishwasher ...). Some of them are handy and useful (pull-out tap, pull-out larder, granite surfaces etc. ...) But the giant sink, now, we would always have such a thing if we could.
Having had experience of various kinds as well as sizes of sink, we decided on stainless steel -- easier cleaning, even if it looks less beautiful than some other materials. Now we think we were right about that too.