Question: I guess the title says it all. =) I'm planning to replace my kitchen sink faucet. What type of sealant should I use for the base of the new sink faucet?

Answer: 
Many facuets come with a rubber gasket, so you don't need any sealant, just install the gasket.
the old standard is plumber's putty. this can be used on most surfaces and laminates. If your counter top is a natural stone, especially marble, plumber's putty could stain it. Check with the stone vendor to be sure to use the proper sealant that will not stain the counters.