Entre-Deux-Mers (literally "between two seas") is that area of Bordeaux situated between the Garonne and Dordogne rivers. Here, you can find mostly dry whites made with straight Sauvignon Blanc or Semillon, or a blend (sometimes with a bit of Muscadelle thrown in for good measure...)
Last night, we had a 2004 Chateau Bonnet Entre Deux Mers. This wine was a blend of all three grapes (50% Sauvignon Blanc, 40% Semillon and 10% Muscadelle). While it had a decent amount of crispness, and a bit of lemon/green apple flavor to it, it also unfortunately showed that "hot, alcohol" feeling that you sometimes get from wines where the grapes were too ripe and the alcohol is too high to balance the fruit.
I'm going to try a few more producers from that area (same vintage) and see how they taste. But in general, Entre-Deux-Mers can be a good area for values, which are often hard to find in Bordeaux.