We can all dream about what we would like to reopen, or what should never have closed. Unfortunately, few of our dreams will be fulfilled. Some lines that closed were lost causes even when they were built. Others closed because they were given lousy services, too few, or running at times which made them useless for workers, schools or shopping trips. Other lines had services that were painfully slow - for example the GC main line between Sheffield & Nottingham, badly affected by mining subsidence.
I think that any line serving towns /populations of 20,000 or less have a low chance of reopening. Even 50,000 may not be enough . And some trackbeds are probably now sold / obstructed by new buildings. Ignoring that possibility, and with the mythical "unlimited funds", my first choices for reopening would include:
Eccles - Tyldesley - Leigh - Kenyon Junction.
Blackpool South - Blackpool Central
Poulton Le Fylde - Fleetwood.
Ormskirk - Skelmersdale (with new loop to serve "new town" areas)
Harrogate - Ripon - Northallerton.
Cross Gates - Wetherby - Harrogate.
York - Beverley.
Malton - Pickering.
Leamside line.
Bishop Auckland - Durham - Sunderland - South Shields.
Newcastle - Ashington / Blyth / Newbiggin
(the above three maybe as part of an extended Metro system)
Perth - Forfar - Kinnaber Junction (for Aberdeen)
Rugby - Leicester (LMS route)
Wolverhampton / Walsall - Dudley - Stourbridge Junction (as trams)
Grimsby - Louth - Mablethorpe - Firsby - Boston - Spalding
Spalding - March (some passenger services, but mainly as an alternative freight route.)
Dunstable - Luton (new connection to MML at Luton) (sadly likely to be a bus failway)
Uckfield - Lewes
Horsham (Christs Hospital) - Guildford & Shoreham.
