I do have the actual dates & notes written down somewhere but I'll just off the top of my head approximate for now, these are the one's that I can think of in the North West area..
Connecting lines from Brindle Heath Junction to Agecroft Junction (closed May 1987)
Curve lines from Ashton Moss South Junction to OA&GB Junction (Oldham Ashton & Guide Bridge) Junction (closed September 1991)
The CLC from Cheadle Junction to Woodley Junction (albeit for a short bit down to Bredbury that still remains in use.) (closed as a through route circa 1981/82?)
Of course Hadfield to Penistone (Woodhead Route etc) (closed 18th July 1981)
Godley Junction to Apethorne Junction (closed circa 1980s)
Crowthorn Junction to Guide Bridge (closed circa 1980s)
Glazebrook East Junction to Skelton Junction (closed circa 1982? ish?) some infrastructure still in situ from Skelton to Partington
Arpley Junction to Skelton Junction (closed July 1985)
Blackrod Junction to Horwich Works (last used circa late 1989/early 1990), the branch was in sporadic use until a large section of the branch was stolen by metal thieves who stole a large amount of the track & cable rendering the branch unusable, the foundry switched to road haulage & never came back, in the intervening years more and more of the branch & infrastructure got nicked for scrap until the final end came circa mid 1996 when the actual junction points & crossings were removed at Blackrod Junction (rendering Blackrod Junction no longer a junction)... I was one of the PICOP on that particular T3 that weekend
Helsby West Cheshire Junction to Mouldsworth Junction (closed September 1991) after Helsby West Cheshire Junction signal box got torched in an arson attack whilst switched out, BR didn't think it worth the cost of the resignalling so just took the decision to shut the entire line instead.
Mickle Trafford to Dee Marsh Junction (closed circa 1993/94)
Rose Grove to Padiham Power Station (closed circa July 1993).
These last ones are of closed routes but involve part of them being partially reopened/converted to LRT Metrolink operation but I have included them as they still have a closed to all traffic & lifted section of the route in them.
Gorton Junction/Hyde Road Jct/Trafford Park East Junction (closed circa October 1988) & lifted throughout.. although a portion of the route was reused, relaid & reopened in 2011 as part of the Manchester Metrolink LRT network from Trafford Bar to Chorlton Junction (now called St Werbergh's Road)... the route from Gorton Junction to Chorlton Junction remains closed & lifted
St Werbergh's Road is where the Metrolink line branches off to the Airport, with the route to East Didsbury continuing along the old MR route as far as East Didsbury.
Manchester Victoria East Junction to Thorpes Bridge Junction (Cheetham Hill Loop) (closed 15th September 1998)... although a section of this route has since reopened from Irk Valley Junction, Smedley Viaduct Junction to a new deviation flyover line for again the Manchester Metrolink lines (Oldham & Rochdale line).. the route from Manchester Vic East Junction to a location just west of Cheetham Hill Junction remains closed & lifted.
Oldham Werneth to Oldham Mumps (closed as a heavy rail route & temporarily converted to LRT operation in October 2009) closed completely in 2014 in connection with a new street running deviation running through the town... the route from Oldham Werneth to Oldham Mumps remains closed & lifted.
I haven't really included the full former heavy rail lines of the Bury line, the Oldham loop & the MSJAR (Altrincham line) as they were just "converted" to LRT operation but I thought that I'd mention the last three as they still have a section of route closed to all traffic.