I have to say that on the chart above I like the TTC logo much better than the dull alternatives.
I think you're just attached to it. It fails in readability, even at larger sizes, and is a mess from a technical perspective with the overuse of strokes and thin line weights. There are a lot of other terrible logos there, but some like Tokyo, Hong Kong, London Underground and even nearby Montreal are not only iconic, but well designed and can still be 'read' at minute sizes. The TTC logo really needs to be updated for the modern age, but it doesn't mean you need to discard the overall shape of the shield and ribbon, it just needs to be simplified and refined.
It seems to me the only weak part of our logo is the inclusion of the TTC acronym in the shield. Certainly the shield and wings and could be flattened / modernized if necessary. BUT even next to some of the others above I quite like it. The TTC could, if they had a better brand, change color for lines/transportation type (similar to the roundel color changes in London) however I don't think we need to throw the baby out with the bathwater on the TTC's logo.