This is in our current kitchen, just about to get new one in new house.
Best:
Dual fuel range cooker
Big freestanding fridge freezer with fridge on top freezer underneath. We had an integrated one in our old house and wouldn't bother again as they are so much smaller.
Integrated recycling and compost bins - these were great, especially if they are right underneath the work surface where you're likely to prep most of your food, as ours were.
Integrated dishwasher.
Worst:
Not enough side space to l-h side of cooker - only 30cm before fridge. This really winds me up and if I was designing a kitchen again, I definitely would make sure that there is plenty of side space both sides of cooker, but particularly to the left as our range cooker has a super large hob on the r-h side, so I always work from the left.
Kettle and dishwasher too near each other, so competition between stacking / emptying dishwasher and making drinks.
Pull out larder cupboard - far too heavy when full. Would just get a standard larder cupboard next time.
Things I am prioritising in our new design:
I've read that a perfect triangle in this order - fridge - sink - cooker - is the ideal set up. Although my current kitchen is small, this is the set up that I have now and it works really well as a working kitchen.
In our new place, we will have an open plan kitchen / living room, so a counter top that also doubles up as a breakfast bar between the two rooms means that you can talk to people while preparing the food - great!
Plenty of side space and storage space with high wall cupboards.