The Bourjois Happy Light foundation (€13.00) provides a light coverage and a healthy glow. This stuff really stays put until I take it off at night and doesn't oxidize or get too shiny throughout the day.
For persistent dark circles, the NARS Radiant Creamy Concealer (€30.00) is my best friend. Applied sparingly (it can be cakey otherwise), it stays all day and keeps me looking at least somewhat awake.
Panda eyes. *Shudders*. I won't bother using a mascara if it won't stay put. I trust the Number Seven Stay Perfect Mascara (€15.00) for an entire day without looking in a mirror.
There is one product I never skip when I have a long day ahead of me: Rimmel Stay Matte powder (€5.19). So inexpensive, yet so effective. A little bit of this on my T-zone keeps the shine at bay.
What are some of your working day essentials?