You can, of course, "start from the beginning" by asking your parents to file an immigrant petition for you. However, the "queue" is backed up 7.5 years for the 1st preference category (unmarried sons and daughters of U.S. citizens). So I would suggest filing an application for replacement of your green card. If you did not secure USCIS' OK for an extended absence, and did not return to the U.S. every year, USCIS will likely deny your application for "abandonment of the permanent residence in the U.S." Should that happen, you will have to prove that you did not abandon your residence here. It will be an uphill battle, and you should seriously consider retaining an immigration attorney to handle it. Unless your attorney advises you otherwise, don't come to the U.S. visiting on any kind of a visa or on a visa waiver: such visits will be interpreted by USCIS as proof that you have, in fact, abandoned your permanent resident status in the U.S.
Answered on Sep 13th, 2012 at 10:09 PM