 The goal of this clinical research study is to learn if 2 cycles of high-dose chemotherapy can help to control germ-cell tumors. The first cycle of chemotherapy will include the drugs gemcitabine, docetaxel, melphalan, and carboplatin. The second cycle of chemotherapy will include the drugs ifosfamide, carboplatin, and etoposide. The safety of these drug combinations will also be studied. 