That's kind of a loaded question because the concept of the JSA has come to include most of the legacy characters as well as most of the Golden Age characters including the All Star Squadron, Infinity, Inc., and Young All Stars. That would end up being a really long list so I'll stick with just the JSA and go from there.
Hourman (Rex Tyler) - Zero Hour 3 (he got better)
Dr. Midnight (Charles McNider) - Zero Hour 3
Atom (Al Pratt) - Zero Hour 3
Dr. Fate (Kent Nelson) - he kind of died in the 4 issue Dr. Fate mini from the 80s but then came back and I think his actual death is considered to be Zero Hour 3 even though he later shows up in the Fate amulet for a while in JSA and the Hector Hall Dr. Fate miniseries
Mr Terrific (Terry Sloan) - Justice League of America 171-172
Starman (Ted Knight) - Starman (Robinson series) 71 or 72
Black Canary (Dinah Drake Lance) - either Green Lantern Corps Quarterly 3 or Secret Origins 50. In the GLC book the JSA is at her funeral and in SO she actually dies in the hospital but I think the GLC book came out first. Go figure.
Wonder Woman (Hippolyta) - Wonder Woman (v2) 172
Sandman (Wesley Dodds) - JSA Secret Files & Origins 1
Spectre (Jim Corrigan) - since he was essentially dead for his entire career, I guess you could say his first appearance was his death in More Fun Comics 54. However, if you are looking at the issue when Corrigan finally goes on to his "eternal reward" and leaves the Spectre behind, that happens in Spectre (Ostrander's run) 62
Robin (Earth 2 Dick Grayson) - the end of Crisis on Infinite Earths
Huntress (Earth 2 Helena Wayne) - end of Crisis on Infinite Earths
Star Spangled Kid (Sylvester Pemberton) - Infinity, Inc. 51
Like I said, there are lots more legacy characters that have been brought into the fold that have passed on such as Red Bee, Firebrand, Fury, Silver Scarab, Manhunter (both of them), some of the original Freedom Fighters and some of the revamps like the second Black Condor and the second Phantom Lady, and others but the ones mentioned above were actually members of the JSA and not just legacy characters. Hope this helps.
Keep your eyes peeled.
DC is going to attempt to "fix everything" by bringing all of these guy back on this "new" Earth two that is set right before crisis in some kind of 80's Earth. All of your favs will be alive and kicking and will have nothing to do with these mainstreem goofballs these writers have twisted some into.
I can't wait! I can't wait!