Le Louvre

Paris_Louvre-statues, originally uploaded by david_stirling.

What can you say about the Louvre, other than it is big? It is really, really, really big. Wall after wall of paintings, case after case of antiquities. Honestly, you get desensitized pretty quickly. It is simultaneously the greatest and the worst museum in the world. The sheer volume of stuff makes it very difficult to appreciate any one piece on its own if you try to view the entire place in one day, as most people do (including me).
Here are my three pieces of advice:
1. Do not do the antiquities first. They are the easiest to get to, and therefore they are crowded. Plus, you can easily spend your entire day looking at a thousand sarcophagi, which are amazing, but you'll blow out all your nerve endings and have nothing left for the paintings.
2. Get outside for lunch. While the museum cafeteria is nice as museum cafes go, it's very crowded. It's only a short walk to the nearby square where you can have a much more relaxing lunch and plan your afternoon.
3. Do not save Delacroix for last. It's one of the more distant sections of the museum, and I thought I timed it so he would be my grand finale, but the staff start herding you out of the building 20 minutes before closing and I was out of luck.