While I generally use whatever neutral eye shadow and black mascara manages to find its way across my desk, there are a handful of products I use that I will never replace or substitute. One of them is Caudalie's Beauty Elixir.
It's billed as a part-toner, part-serum, but I consider it a magical potion. It hydrates without being gooey and the smell is so relaxing. I have probably gone through gallons of it since I discovered it, and it's passed liberally around the Fashionista office, too. (Yes, I share. It's too good not to.)
You can squirt it at night before bed on a clean face, or over makeup during the day if you need a dewy little pick me up. Did I mention the smell? It's like a mini spa treatment in a chic little glass bottle.
Get it here.