None of the Before Watchmen books can compare to the original storyline, but some of the BW books are worth reading.
This is how I'd rank them:
1. Dr. Manhattan
5. Silk Spectre
For the record, I view both the Rorschach & Comedian books as crap.
I'll give a short summary on what I consider to be the two best titles:
Dr. Manhattan has an interesting premise, and is written well. It also has amazing interior art by Adam Hughes (Who usually only does cover art).
Minutemen gives more of a back-story on various characters, but you may not like a select few bits of the added material. For instance, I took exception to the original Silk Spectre, in issue #1, being shown to have had a sham background as a superhero. I could be mistaken, but I don't remember that being in the original storyline, and, for whatever reason, I found it distasteful.......In later issues, there's negative back-story on another character which I find to be unnecessary.......Of course, the pacing and overall artwork by Darwyn Cooke is excellent, and his writing style is a perfect fit for the title. I just think he tried to go for a little too much with the two nitpicks I stated previously. I have enjoyed the extra coverage on Nite-Owl I, Silhouette, Mothman, and even Dollar Bill (However limited that extra coverage was).