As a foreigner, despite three visits to your nation(s), I've not alighted at as many stations as many of you, but I thought Machester Piccadilly in late 2022 (second visit) was excellent: a booking office adjacent to platforms and lots of retail that wasn't in the way. Heavy patronage: great, and a good escalator to Manchester Metrolink though returning from the ELR, the 'up' one was inoperable: the lift sufficed.
I did not like Manchester Oxford Road's island platform. Poor train information indicators, and peak period commuters (even with reduced numbers post-COVID-19) struggling to get through barriers efficiently. It was difficult to walk down from the nearby mini Sainsbury's and try to enter the barriers when a crowd was exiting onto the station access road.
I spent half an hour changing train at Hellifield: the area with the building was barricaded as the cafe was not open (on a Monday, IIRC?) but in contrast to one poster above, it looked OK (though couldn't see the brickwork and windows close up).
It was difficult at Leeds to change trains quickly: I missed a Bradford Forster Square service by 30 seconds as burdened with luggage it took a while to work out from which platform the train was departing.
Shipley station had a strange layout where to change trains to get to Bradford Forster Square I had to race up and down a footbridge in the rain, after half running with my suitcase and backpack across a fairly grotty carpark at night.
On a previous visit in 2013, I thought an intermediate station on the Saltburn line (out of Darlington) was grotty and unappealing. Maybe it was the Redcar one at the closed steelworks?
Edinburgh was OK but arriving at 0630 on Caledonian Sleeper on a strike day, I found the layout confusing, perhaps testimony to how I'd slept poorly in the less than ideal CAF-manufactured sleeping car.
Lancaster was an especially beautiful station and staying at Preston (Lancs) for three nights, I loved it but stupidly managed on my first visit to find myself in some subway that was deserted and perhaps unused. Dumb foreigner the locals would have thought had they seen me, and cannot even plead that English isn't my first language.
Carlisle was also attractive.