60s and 70s Decade would make great teams.
DC owns tons of heroes from several companies. The 30's and 40's having created the most original heroes. As you can see from the following lists, DC started to revise older heroes from the Golden age after the 60's and 70's rather than create new heroes.
Here are my ideas for teams based on what decade they were introduced:
1960s Heroes Team
1970s Heroes Team
Black Orchid , Adventure Comics #428, 1973
Rose and Thorn, Superman’s Girlfriend, Lois Lane #105 1970
Black Lightning, Black Lightning #1 April 1977
Shade the Changing Man, Shade the Changing Man#1 1977
Mister Miracle, Mister Miracle #1 1971
Firestorm, Firestorm #1, 1978
After the 70's DC really didn't created too many new heroes. I will admit that there were heroes created, but non more memorable than the lists above.
Starman (Jack Knight)