I can't remember what issue it was of Supergirl but I recently read the one where the "Wonder Twins" appeared on the scene and Supergirl helped them fight a giant monster from their dimension. She got knocked out and was having visions of being back in the future with the Legion.
There's a two page spread of Supergirl flying above the Legion while they cheer her return. It was so cool looking! Seeing her and the Legion thrilled at seeing each other again really made me want to check this series out.