There's one called "The Essential Appetizers Cookbook" put out by WhiteCap Books. It's got alot of good and colourful ideas. Many can be made ahead. To be honest, I picked it up for a few dollars at Borders Books on the bargain table not long ago -- they still have it. I think one of the things I like best is that they have some good presentation ideas. A new take on the same old...
Martha's Book is beautiful. Not always very practical unless you have a huge staff--or just a few to cook for!! But the recipes are good, I serve several of them here-
and the blue cheese popovers are really good if you add extra bleu!