What bus have you used the most in your life?

Mine is probably the 47 (Catford - Liverpool St.)

Probably 271 which is the bus from Holloway to Old Street that goes down New North Road instead of Upper Street.  Goes to my old office, to Highbury (for pool or hopping on overground or switching buses), to Cara's old flat, to Liverpool Street

This year I have been putting in a lot of time on the 191 Highway 27 express bus from Kipling Station to Humber College.  Aside from travelling to far-flung suburban campuses I try to avoid the bus as much as possible in Toronto, opting for subway and streetcar. Apparently this bias against buses is widely held - studies show that to get commuters to give up their cars you have to offer them some sort of rail-based transport (trams will do) as they are averse to buses.

My local bus is the 47 Landsdown but its infrequent and doesn't really go anywhere I want to go (aside from an old streetcar suburb called Parkdale that has some decent bars and shops).  My second closest bus is the much more frequent 29 (!!!!!) Dufferin and as of recently its a bendy bus (!!!!!!!!!!!!).  I look forward to the mayhem that will ensue when the TTC finally introduces proof-of-payment system on these.

41 Keele to get to York University through some of the crummiest and bleakest parts of suburban Toronto. I am particularly fond of the express service, but you have to know the timetable to take advantage of it. It just got some bendy buses too and I think they're great. I think Toronto is a sufficiently rule-abiding city that all door boarding will probably go pretty smoothly.

Have been enjoying the Dupont bus lately, but now that warm weather has returned my TTC time will be limited.