After a long time filming lots of clips of trains from every UK TOC (excluding London Overground) travelling at speed, here is the final result. This video features trains travelling at high speed (mostly over 75mph apart from London Underground and TfL Rail) from the following TOCs:

Abellio Greater Anglia
Arriva Trains Wales
c2c
Caledonian Sleeper
Chiltern Railways
CrossCountry
East Midlands Trains
Eurostar
Govia Thameslink & Great Northern
Grand Central
Great Western Railway
Heathrow Connect
Heathrow Express
Hull Trains
London Midland
London Underground
Merseyrail
NIR Translink (Northern Ireland)
Northern Rail
Scotrail
Southeastern
Southern (GTR)
South West Trains
Transpennine Express
TfL Rail
Virgin Trains West Coast
Virgin Trains East Coast

Enjoy!