IMO the Saints have a clear top three of:
1. Drew Brees
2. Willie Roaf
3. Rickey Jackson (2 and 3 could be swapped in order).
After that, there are a whole bunch of guys who were very good, but not "all timers".
Jahri Evans is well on his way to joining those three and with another couple of years he gets there.
The other three members of the Dome Patrol should all merit discussion.
Colston and Horn both get discussion, and obviously Colston is still playing so he could increase his chances.
Morten Anderson was really good.
IMO Deuce McAlister and Archie Manning were both good players but are a bit overrated b/c they were the best parts of bad teams, so people have very fond memories of them doing a lot of good things.