You used to be able to catch an old style Routemaster on the number 15 Heritage Route and you can catch the new style Routemaster buses on the following routes:
The number 03 – Crystal Palace to Conduit Street
The number 08 – Oxford Circus to Bow Church
The number 09 – Hammersmith to Aldwych
The number 10 – Hammersmith bus station to King’s Cross St. Pancras
The number 11 – Liverpool Street station to Fulham Broadway
The number 12 – Dulwich to Oxford Circus
The number 15 – Trafalgar Square to Blackwall DLR – Heritage Route
The number 16 – Victoria station to Longley Way
The number 21 – New Cross
The number 24 – Hampstead Heath to Pimlico
The number 38 – Victoria to Hackney
The number 48 – Ash Grove
The number 55 – Oxford Circus to Leyton
The number 59 – Telford Avenue to King’s Cross station
The number 68 – West Norwood station to Euston bus station
The number 73 – Victoria to Stoke Newington
The number 76 – Northumberland Park
The number 88 – Camden to Clapham
The number 91 – Holloway
The number 137 – Oxford Circus to Streatham Hill
The number 148 – Camberwell Green to White City bus station
The number 149 – Edmonton Green bus station to London Bridge station
The number 159 – Streatham station to Marble Arch
The number 168 – Royal Free Hospital to New Cross/Peckham
The number 189 – Cricklewood
The number 211 – Battersea
The number 253 – Hackney Central to Euston
The number 254 – Stamford Hill
The number 390 – Notting Hill Gate to Archway
The number 453 – Marylebone station to Deptford Bridge
EL1 – Ilford Hill to Riverside Campus
EL2 – Becontree Heath Leisure Centre to Dagenham Dock Terminus
EL3 – Chadwell Heath Lane to Riverside Campus
N3 – Oxford Circus Station / Margaret Street to Bromley North Station
N8 – The Lowe to Holles Street
N11 – Ealing Broadway Station to Great Winchester Street
N15 – Romford Market to Margaret Street / Oxford Circus
N16 – Edgware Bus Station to Victoria Bus Station
N38 – Walthamstow Bus Station to Victoria Bus Station
N55 – St Thomas Of Canterbury Church to Oxford Circus
You are able to use the Oyster card on both the London Underground and the new style Routemaster buses.