Sorry if this has been mentioned before, but I could not find it via the search.

 

Anyways, if I recall correctly Sammael was kill in SL by Marshdar (sp). Could the DO save him like he did withthe 'gars. Basically could Sammael be alive somewhere and we dont know where?

I think the consensus is that because Sammael was killed by Mashadar his soul was devoured, thus out of the DO's ability to ressurect, or people killed by the Taint of Aridhol are in parallel opposition to the DO's power and thus unable to be ressurected.

To quote Robert Jordan:

 

Sammael is toast

 

Also, BS said that "the DO would have liked very much to transmigrate Sammael but didn’t. Apparently, since he died by Mashadar, Sammael was either unable to be transmigrated or it would have been a very bad idea. Basically, Mashadar tainted Sammael’s thread somehow". (Q&A)