For years I just rode the Métro, or subway. There are some 300 stations in Paris, so you're never far from one. In the early '70s, when I was living in places like Aix-en-Provence and Rouen, I would go to Paris as often as I could. Then in 1974 I got a job in Paris and found an apartment in the close-in suburb of Asnières-sur-Seine, near Courbevoie and Levallois-Perret on the western edge of the city.
I lived right next to the Asnières train station. I could take a commuter train three stops or so to the Gare Saint-Lazare, and there I could transfer to the Métro. I was working in the Latin Quarter, so it was a long ride. I spent so much time underground that I started to feel like I was living the life of a mole. Or an ant. At rush hour, the trains were packed like proverbial sardine cans. Sometimes the platforms (les quais) were so crowded that you feared you might just get pushed off and fall on the tracks in front of a speeding train.
Then in 1974 or '75, the Métro system introduced the Carte Orange, a monthly pass for unlimited travel on public transit all of over the city. I was on a tight budget, so it was nice not to have to buy so many single-ride tickets every week. The Carte Orange saved me a lot of money. And one of the best benefits it provided was that it was also good on the buses that run all around the city at surface level instead of in underground tunnels.
So I started riding the buses. That's a lot more fun, because you can see where you are. With the monthly pass, you could jump off the bus whenever you saw something interesting to explore, and jump back on without having to buy or use a second ticket. In fact, most bus rides of more than three or four stops in Paris cost you two tickets anyway. Unlimited travel on buses changed my life. The downside: buses can get caught up in traffic jams.
Even so, the best way to get around in Paris was to walk. The rain be miserable, and you always to had to be careful not to step in the dog poop that littered the sidewalks. Or worry about getting run over by some crazed driver when you were crossing the street. Anyway, walking around the city was good exercise. From 1979 to '82, I lived just 10 steps off the rue Montorgueil near Les Halles. I could walk to the Latin Quarter or to Saint-Germain-des Prés, where I was working back then. What a different life that was.