I use DVD Decrypter for backing up my XBox and PS2 games, if PC game mount the image on virtual drive and play it without burning the disk, if you want it on disk would suggest making sure you have a DVD Writer, if burning Xbox dual layer games a special DVD dual layer DVD burner if required, a standard dual layer DVD drive will not work with Xbox games as the firmware needed to be modded inside the dual layer DVD burner, any games not related to Xbox should burn on a standard Dual Layer.
Depends on the type of game though, what platform it is on, pc, xbox, ps2, Wii, etc, with Xbox will also need to update filmware on occation depending on which Ixtreme flash software installed on the modded xbox.
Currently playing Saint Row 2, tis the dogs bollox.