The following counties (in England) have 6 or more TOCs serving it:
Cheshire - 8 (TfW, EMR, Caledonian Sleeper, WMT, Northern, CrossCountry, Avanti West Coast, Merseyrail)
Greater London - 17 (Southeastern, WMT, Avanti West Coast, Overground, Caledonian Sleeper, c2c, LNER, Thameslink-GN, Hull Trains, Grand Central, Greater Anglia, Tfl Rail, Chiltern Railways, GWR, Southern, SWR, Eurostar)
Greater Manchester - 6 (Northern, TransPennine Express, TfW, CrossCountry, EMR, Avanti West Coast)
Hertfordshire - 10 (Avanti West Coast, WMT, Southern, LNER, Hull Trains, Thameslink-GN, EMR, Chiltern Railways, Greater Anglia, Overground)
City of London - 6 (TfL Rail, Thameslink-GN, Southeastern, Greater Anglia, c2c, Overground)
Merseyside - 7 (Merseyrail, EMR, WMT, Northern, TransPennine Express, TfW, Avanti West Coast)
North Yorkshire - 6 (CrossCountry, EMR, TransPennine Express, Grand Central, LNER, Northern)
South Yorkshire - 7 (CrossCountry, EMR, Hull Trains, TransPennine Express, Grand Central, Northern, LNER)
West Yorkshire - 6 (CrossCountry, LNER, EMR, TransPennine Express, Northern, Grand Central)