Check out the Collins line of products. There's one that's designed specifically for stretch marks, and it's awesome. Doesn't get rid of them (it's essentially scar tissue, pretty impossible to get rid of unless you go for a pixel laser surgery that punctures tiny little holes in your skin and causes new skin to grow), but this stuff flattens out stretch marks if they're deep, causes them to tighten up / shrink a litlte bit, and fade from red to silvery/skin tone.
If your stretchmarks are still red/pink and you want a more permanent treatment, go to a cosmetic surgery place (usually places where they do body resculpting, botox injections, microderm abraision, etc) and get an assessment done. My understanding is that there's greater success when they're still red - if they've turned silver/faded, it's more difficult to treat with surgery. However, surgery is expensive and will involve several passes.