In terms of freight traffic on the B&H (primarily between Westbury & Reading), the common runners are as follows in the up direction -
6A29 Merehead - Hanwell/Southall
6A31 Whatley - Theale ARC
6O98 Whatley - Allington (Stoke Gifford on Mondays)
6A40 Merehead - Hanwell
6Z52 Tytherington - Quainton Road (DCR)
6A18 Whatley - Oxford Banbury Road
6A50 Whatley - Hanwell
6A60 Merehead - Colnbrook (MWFO)
6A99 Merehead - Theale FY (TTHO)
6A61 Whatley - West Drayton
6A70 Whatley - Dawley Loop
6M18 Merehead - Willesden Sidings (DCR)
6A80 Merehead - Hanwell
6M47 Whatley - Cricklewood (DB)
6A90 Merehead - Hanwell/Southall
6A00 Whatley - Hanwell/Southall
6A10 Merehead - Hanwell/Southall
6A19 Merehead - Hanwell/Southall
And in the down direction -
6V80 Wembley - Whatley
6V90 Wembley - Merehead
6C60 Colnbrook - Merehead
6V14/0V14 Cliffe Hill - Westbury Yard (Colas)
6A11 Robeston - Theale Puma (DB)
6V20 Wembley - Merehead
6C52 West Drayton - East Usk Yard
6C31 Theale ARC - Whatley
6V31 Wembley - Merehead
6V40 Wembley - Merehead
6V18 Oxford Banbury Road - Whatley
6Z23 Wembley - Tytherington
6V50 Wembley - Merehead
6V60 Wembley - Whatley
6V70 Wembley - Merehead
6V10 Acton Yard - Whatley (DB)
6C99 Theale FY - Merehead
6C62 West Drayton - Whatley
Worth noting, these don’t all run everyday, but they’re the more regular runners that often run a few times a week at least. There are other paths that run much more occasionally.