A good clear gloss finish
Nothing brings out the color of wood like a good quality clear gloss finish.
The best application is by spraying. I dont know if you have a spray gun or not, but if you do I would suggest a high quality catalyzed lacquer or a high quality conversion varnish.
When you have glued up your top, sanded it and are ready to finish it, wipe it with a wet rag full of thinner. THis will show you pretty much how it will look when the finish is applied. A pretty wood like walnut should not be stained, the stain hides some of the grain. A satin finish diffuses the reflection of light and also hides some of the grain features.