Angelina is on the rue de Rivoli in the 1st arrondissement. There's also a branch at the Galleries Lafayettes -- which is the one I've visited a few times. It's a good spot for lunch -- omelettes, salads, sandwiches and great desserts. Heres an entry from my travel journal when I took my niece to Paris in October 92:
...I ordered the salade Angelina, which consisted of an enormous portion of frisée, green beans, sliced hard-boiled eggs, chunks of chicken, thin slivers of ham, and some kind of mild-flavored cheese, bathed in a mustard vinaigrette dressing.
Both of us were careful not to eat too much because we knew the best was yet to come: their famous hot chocolate made of melted chocolate bars. We ordered a pot for two and a couple of tiny fruit tarts, one strawberry and one raspberry. Imagine it: a pitcher of molten milk chocolate, along with a bowl of freshly whipped, barely sweetened cream. It was only divine. After we finished -- and we could finally stand up -- we immediately went to the candy counter and bought a couple of packages of hot chocolate mix to take home.