Arthur Curry / Aquaman

Earth-One / Post-Crisis / New Earth

 * 1)  Diana / Wonder Woman  - In a retcon, it was established that, while they were still teenagers, Arthur saved Diana from an angry sea god. The two then shared a kiss.
 * 2) Mera - This princess from another undersea kingdom in another dimension has almost always been his main love interest. They were married, and had a child, Arhtur. After their child was killed by Black Manta, Mera went insane, and their marriage ended.
 * 3) Power Girl - An attraction to, or shared with, Power Girl, was teased at some point in Justice League history.

Aquaman eventually began having romantic tension with Wonder Woman. While under the lasso of truth, he admitted both that he found her attractive, and that she was the main reason he stayed on the team. At another point, as Wonder Woman had been put under a Snow-White-like spell, he awoke her with a kiss.
 * 1) Dolphin - Aquaman had a brief liaison with Dolphin. Ironically, she would go on to marry his surrogate son, Garth. (Aquaman #12)

Eventually, Arthur would go on to reconcile with Mera.

New 52
 
 * 1) Mera is still his main love interest on Prime Earth.

Kingdom Come

 * 1) Dolphin - In this “future” story, written after Arthur and Mera’s separation Arthur is now married to Dolphin.

==  Adaptations  ==

Smallville

 * 1)  Lois Lane  - When a teenage Arthur first visits Smallville, he rescues Lois from drowning. He then begins pursuing her, and the become something of an item. After the mission he set for himself is completed, he leaves town, and bids Lois farewell.
 * 2)  Mera  - Arthur returns to Smallville later a married man, to Mera.

Aquaman (pilot)
In the pilot episode of his own would-be series, Arthur is best friends with a girl named Eva, and meets an Air Force (or Navy? Or Marine?) pilot named Lt. Rachel Torres, whose life he saves when her plane crashes in the water. It was already apparent in the episode that Eva had a crush on Arthur, but Rachel was reportedly intended to be his main love interest on the show. Regardless, it appeared that the writers intended for a love triangle to take place.

DC Extended Universe
 
 * 1) Mera - Arthur met Mera, a resident of Atlantis, in Justice League. After she helped him gian the throne of Atlantis, the two shared a kiss and apparently became a couple.