Following in from the thread on "three railways I wish I had experienced", I've written myself a similar list - but this time not trimmed - of those I did use before their demise as part of the national network

Firsby to Lincoln
Shanklin to Ventnor
Taunton to Minehead
Haltwhistle to Alston
Wareham to Swanage
Alton to Winchester
Uckfield to Lewes
Tunbridge Wells Central to Eridge
Paignton to Kingswear
Blackfriars to Holborn Viaduct
Broad Street to Dalston Junction
New Holland [Town] to New Holland Pier
Craigendoran Pier to main line
Balloch Central to Balloch Pier
Paisley Canal to Kilmacolm
Glasgow High Street to Bridgeton Central
Spalding to Boston
March to Spalding
Aberystwyth to Devils Bridge
Selby (direct) to York
Bedford St Johns (Old station)
Darnall to Penistone
Sandhills to Liverpool Exchange

Some are very vague memories - but some are strong even if a long time ago ...