Things that you can ALWAYS find in Paris within a block's radius.

1. Pharmacie: Even the French admit it, every two steps you walk in Paris, you're never far away from the bright green neon light of a Pharmacie.  They do come in handy, especially when I got sick a gazillion times this past winter, and also the fact that I tend to hurt myself rather easily.
But really?  With all the Pharmacies around, you'd think that the French are all infected with some kind of illness or diseases.
There's also the "Parapharmacie" that sells body care products and such.  It's rather bizarre to see famous brands like "Biotherm" on its shelves, when they are sold at fancy department store counters in Taiwan.

2. Brasserie:  I love the multi-functionality of a French Brasserrie.  In the morning you can go and have a coffe with croissant or tartine.  At lunch, they serve lunch with very reasonable prices (usually around 10 Euros for the plat du jour).  In the afternoon, you can go and have coffee or a late-afternoon drink.  And of course dinner at night.  For me they are an excellent choice to rest my legs when I'm tired from exploring the city!
I can serious picture before the banning of smoking that these Brasseries were filled with non-stop smoking customers just chatting away.

3. Boulangerie:  The French love and need their bread for every meal, so it is essential for the existence of boulangeries every other step.  And also, you can even find some that are open on Sunday nights *gasp*
There is nothing better than passing by a boulangerie in the morning and smelling fresh baked bread.  I used to pass by one on my running route, and it'd kill me every time!  I guess since I'm not from here, I like to try out different boulangeries, since the quality differs emmensely.  But there are many French people who swear only by one boulangerie!!
Oh and just a side note, for some reason many of the award winning boulangeries are around the Montmartre area.  But so far my favorite baguette tradition is from a place called "les Ateliers des Pains" near Place de Clichy.

4. Banks:  I think Taipei and Paris should go head to head in who has the most banks in a hundred meter radius.  BNP Paribas, Societe Generale, Credit Agricole, Banque Populaire, Credit Cooperatif, Caisse d'Epargne, HSBC, etc.  I think I can find all of these on Boulevard Voltaire.  Oh not to mention the Post Office also offers banking (and oddly, cellphone service).

5. Small super market chains: Franprix, monoprix, casino, etc.  They're convenient to a certain point, but what I don't like about them is it takes away my joy of shopping at local butchers, cheeseshops, wine shops, seafood shops, etc.  Their existence has also taken a lot of business from small shop owners.  Most of them are owned by the Casino Corporation. 

6. Traiteurs: which are more or less take out joints.  I'm actually really surprised how often the French eat pre-prepared food. 

7.  Ok I have to mention this again... DOG SHIT: and this is something you find every step of the way!