Somewhere in the list, withdrawn then number reused again:-
Service 8 (in 1980s) - Bedok to Shenton Way
Service 8 (current) - Toa Payoh to Tampines
Service 11 (in 1980s) - Somapah to New Bridge Rd
Service 11 (current) - Geylang Lor 1 to National Stadium
Service 28 (withdrawn in 1992) - Tampines to New Bridge Rd
Service 28 (from 1995) - Tampines to Bedok, then extended to Toa Payoh in 1998.
Service 34 (1994-2002) - Bedok to Changi Airport
Service 34 (current) - Punggol to Changi Airport
Service 54 (in 1980s) - Hougang to Eunos
Service 54 (current) - Bishan to New Bridge Rd
Service 55 (in 1980s) - South Canal to Mei Chin Rd
Service 55 (current) - Bishan to Siglap Rd
Service 57 (before 1986) - Commonwealth Ave to Changi Airport
Service 57 (1988-1992) - Bishan to Sin Ming Ave
Service 57 (current) - Bishan to Bt Merah
Service 58 (1988-1991) - Bishan to Marina Ctr
Service 58 (current) - Bishan to Pasir Ris
Service 59 (before 1999) - Bishan to Jln Kayu, shortened to AMK (now become service 86 from Sengkang to AMK)
Service 59 (current) - Bishan to Changi Village
Service 60 (in 1980s) - MacPherson to Shenton Way
Service 60 (current) - Eunos to Bedok
Service 72 (withdrawn in 1992) - Serangoon to Tg Rhu
Service 72 (today) - Yio Chu Kang to Tampines
Service 80 (1997-199

- Hougang Ctrl to Tampines
Service 80 (current) - Sengwang to Harbourfront
Service 83 (withdrawn 1993) - Punggol Rd End to New Bridge Rd
Service 83 (current) - Punggol to Sengkang
Service 85 (in 1980s) - Hougang to Sims Ave
Service 85 (1998-2003) - Sengkang to Harbourfront
Service 85 (current) - Punggol to Yishun
Service 90 (in 1980s) - Buona Vista to PLA
Service 90 (current) - Toa Payon to PLA
Service 91 (in 1980s) - Geylang Lor 1 to PLA
Service 91 (current) - Buona Vista to Ayer Cres
Service 92 (withdrawn in 1993) - Clementi to PLA
Service 92 (current) - Science Park Dr to Mt Sinai
Service 95 (in 1980s) - Clementi to PLA
Service 95 (1990 onwards) - Buona Vista to NUH/NUS
Service 101 (in 1980s) - Serangoon to New Bridge Rd
Service 101 (current) - Serangoon to Buangkok Dr
Service 138 (in 1980s) - AMK to Shenton Way
Service 138 (current) - AMK to Zoological Gdns
Service 148 (in 1980s) - Toa Payoh to Buona Vista
Service 148 (1991-1992) - Clementi to Geylang Lor 1
Service 151 (in 1980s) - Toa Payoh to New Bridge Rd
Service 151 (current) - Hougang to Kent Ridge
Service 161 (in 1980s) - Sembawang Rd End to Shenton Way
Service 161 (current) - Woodlands to Hougang
Service 162 (in 1980s) - AMK to Sims Ave
Service 162 (current) - YCK to Shenton Way/Marina Ctr
Service 168 (in 1980s) - AMK to Orchard Rd
Service 168 (current) - Woodlands to Bedok
Service 175 (in 1980s) - Shenton Way to Tuas
Service 175 (current) - LCK to Upp Bt Timah (now 975)
Service 177 (in 1980s) - Bt Timah to CCK Rd End
Service 177 (current) - Bt Batok to Bt Panjang
Service 179 (in 1980s) - CCK to New Bridge Rd
Service 179 (1993-1999) - CCK to Fajar Rd
Service 179 (current) - Boon Lay to NTU
Service 180 (in 1980s) - Marsiling to Shenton Way
Service 180 (current) - Bt Panjang to Boon Lay
Service 183 (1998-2001) - Tuas to Tuas West Dr
Service 183 (current) - Jurong East to Kent Ridge
Service 184 (in 1980s) - Bt Merah to Jurong
Service 184 (current) - Bt Panjang to Clementi MRT
Service 186 (in 1980s) - Clementi to Shenton Way
Service 186 (current) - Shenton Way to St Michaels
Service 188 (before 1987) - Ulu Pandan to Shenton Way
Service 188 (1989-1991) - Jurong to Jurong West St 91
Service 188 (current) - CCK to Harbourfront
Service 192 (in 1980s) - Jurong to Shenton Way
Service 192 (current) - Boon Lay to Tuas
Service 193 (in 1980s) - Princess Elizabeth to Shenton Way
Service 193 (current) - Boon Lay to Tuas
Service 194 (in 1980s) - South Canal to Yong Siak Street
Service 194 (current) - Boon Lay to Jurong Bird Pk
Service 804A (before 1999) - Yishun to Yishun Ring Rd (now 806)
Service 804A (current) - short trips to Northbrooks Sec Sch during weekdays
Service 857 (1992-1996) - Yishun to Adm Rd West
Service 857 (current) - Yishun to Suntec City
Service 950 (1989-1996) - Marsiling to Shenton Way
Service 950 (current) - Woodlands to JB