I know a really good one. I think it's called Brilliant White...I got mine from Superdrug for about 5 squid. It's in lilac, green and white packaging and comes with three tubes of different gel & toothpaste and a mouth guard. You rub this stuff onto your teeth then you put the gel into the mouthguard and leave it in your mouth for about 5 -10 minutes i think...I used it morning and night to get my teeth white after I stopped smoking and it really worked...even after a couple of days I could see a difference. Be persistent though as some stains may take longer to shift. Also, try and drink herbal teas and stay away from red wine & fags!