Another teeth whitening question...?

Alright so i want to get my teeth white of course. i do smoke heavily and i know that's horrible on my teeth and im trying to slow down. but i was at the grocery store today and was looking at the teeth whitening stuff. and was like wow there so many different kinds how do i pick what right for me ? or how would i even know it works ? so basically i would like to know what type of products you have used if it was the trays or the strips or the gel. before i go spend 40$ on a chance of what will work i would like an second opinion. thx
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I like using Classic Crest Whitestrips. I haven't tried any other brands besides Crest Whitestrips, but they have not given me any reason to! I've used them probably 3-4 times over the past 3-5 years. Works great :) But I know they have speedier ones out now that take like 5 minutes, but I know they're more expensive.
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