Of the currently available U.S. DVDs out there, the Image release is probably the best authored. Wade Williams claims ownership of the copyright for this film, so the Image release is the "official" version.
Strangely, a lot of PD prints of D.O.A. don't look that bad. The problem for DVD releases comes with the over-compression that most bargain labels employ (combined with sometimes using a VHS copy as their "master.").
I think that Roan at one time had this out on DVD, and that version was pretty good as well.