Mine aren't real bad, but years of drinking soda has left the bases of some of them a little stained. Luckily I've never smoked so they aren't TOO bad.
I'm trying those Crest Whitening Strips but man o man I don't know if I can stick out the 14 day regimine.
What a horrid taste, and it's so hard to leave these things on for 30 minutes and not mess with them.