I'd say the latest version (v25). There is a lot of missing functionality, but you can still do all the important stuff (like adjust paragon/renegade scores, ME1 decisions for import purposes into new ME2 game, add squadpoints, add minerals etc). Dogmatix314 21:55, November 7, 2011 (UTC)
I think Pordis Shepard's modified Gibbed's save editor is best, at least for 360 files.
This seems a bit better editor. I just hadn't heard of it before. I haven't really tested this so I can't say if the editor makes ME3 compatible savegames. Although nobody can be sure of the original editor either. Dogmatix314 08:20, November 9, 2011 (UTC)