For me

Newcastle-London
Newcastle-Berwick
Newcastle-Edinburgh
Newcastle-Aberdeen
Newcastle-Manchester Airport
Sunderland-Newcastle
Sunderland-MetroCentre
Sunderland-York
Sunderland-Eaglescliffe
Sunderland-Hexham
Seaham-York
Seaham-Middlesbrough
Seaham-Hartlepool
Seaham-Thornaby
Durham-London
Durham-Doncaster
Durham-Newcastle
Durham-Darlington
Durham-Sheffield
Sheffield-Durham
Sheffield-Nottingham
Nottingham-Derby
Derby-Durham
Thornaby-Darlington
Middlesbrough-Darlington
York-Doncaster
York-Grantham
Hull-York
Durham-Sheffield
Sheffield-Derby
Derby-Nottingham
Sunderland-Liverpool
Durham-Liverpool
Lowestoft-Norwich
Norwich-Peterborough
Peterborough-Durham
York-Leeds(via Harrogate)
York-Leeds(TPX)
Manchester Victoria-Leeds(via Rochdale and Bradford)
Waterloo-Redruth
Redruth-Exeter
Exeter-Plymouth
Plymouth-Paddington
Grantham-Skegness
Liverpool-Euston
Waterloo-Pompey
The entire Isle of Wight Island Line
Manchester Victoria-Liverpool
Newcastle-Manchester Airport
Leeds-Halifax
Edinburgh-Dundee
Dundee-Aberdeen

all i can think of right now