Cassie Sandsmark / Wonder Girl

Post-Crisis / New Earth
A mourning Wonder Girl became obsessed with bringing Superboy back, and became involved with the corrupt “Cult of Conner” (52). Eventually, she gave up on this and erjoined the Titans. While she dated Tim, the Legion of Super-Heroes used 31st century super-science to revive Superboy (Legion of 3 Worlds #4-5 [2009]). After defeating Superboy-Prime, Conner returned to his proper time and reunited with an elated Wonder Girl.
 * 1)  Kon-El / Conner Kent / Superboy  It was love at first super-sight for Wonder Girl. Upon joining Young Justice, Cassie Sandsmark was instantly smitten with Supeboy (Young Justice #4, 1999). The cocky Teen of Steel remained unmoved by Cassie’s affections. Cassie matured as a member of the team. Superboy finally realized he had fallen in love with Wonder Girl, and declared his feelings to her ), culminating in a long-deserved kiss. (Young Justice #55, 2003) The romance continued in the pages of Teen Titans [2003], despite Wonder Woman’s initial disproval (TT #6) and Superboy’s Luthor-initiated rampage (TT #24-35). And when the Infinite Crisis threatened all of existence, Cassie and Conner consummated their relationship  (TT vol. 3 Annual #1, 2006). Heartbreak followed, as Superboy seemingly gave his life, dying in the arms of Wonder Girl  (Infinite Crisis #6-7)
 * 1)  Tim Drake / Robin  was another Titans teammate and Conner’s best friend. He and Cassie found solace in each other after Conner’s death and became an item.

New 52

 * 1)  Tim Drake / Robin  - In the New 52, Tim once again is into Cassie, while Superboy also has a thing for her. A Robin mind-controlled by Trigon sleeps with Cassie, while also making out that same night with Solstice (who was dating Bart Allen). Im not sure how that worked out.

==  Rebirth  ==
 * 1)  Conner Kent / Superboy  - It seems these two are an item again.