Key words: "done well" and "good public transport".
Whenever I see discussions like this, I always feel the standards that most public transportation advocates consider "good" or even "acceptable" are far lower than mine.
Mine - Seoul, Tokyo, other East Asian cities.
Most public transportation advocates - Maybe NYC, many even lower.
Factors - reliability, cleanliness (both cars and stations), reach, safety (both actual and perceived, and both violent and non-violent).
Give me the Seoul or Tokyo subway and I'll gladly ditch my car (actually...no, but I'd only use it for excursions outside the city).