Cyanogenmod is a popular ROM, but Motodroid development is falling behind. The current nightly experimental build is based on Gingerbread and working towards becoming a stable release candidate. Meanwhile most other CM-supported phones are on their second release candidate.

Regardless, I use the latest stable version for Droid 1, which is version 6.1.2, and seriously recommend keeping your eye on Cyanogenmod, it has some very nice features.