Here we go
 
1: Rainbow Dash x Flash Magnus  
Ever since Flash’s return from limbo, Rainbow admired him from a distance (other than when she went with him to help save Equestria). After discovering Flash Magnus shared similar feelings, the two began to date, and it wasn’t long before they were a happily married couple with 3 foals. Flash and Rainbow are both very competitive and use this common trait to help each other grow. They do have arguments sprinkled into their relationship, but most last a week at most. They’ve made it their mission to show their three foals the world and help them become confident little colts.
 
2. Celestia x Discord  
From the start, even before reformation, Discord had a slight crush on Celestia, though at the same time he was envious of her. However, after reformation, he mostly had his eyes on Fluttershy, and, for awhile, the two dated. For a long time, Discord was very protective of Fluttershy and was very resentful of anypony he saw as too close to her. This lead to them breaking up, as Fluttershy found a different pony she liked and began to catch on to Discord’s clinginess. Heartbroken, it was Luna who directed Discord to Celestia in his dreams. Soon, Celestia and Discord were having frequent visits to each other. Soon, they got into a relationship. What made Discord love Celestia so much was how she shamelessly displayed and defended her love for him. Celestia loved the chaos and fun he brought into her life, and Discord loved the acceptance Tia gave him. The pair almost never argues and makes an effort to present their issues to each other as quickly as possible. They sport a healthy relationship and two heirs to the throne.
 
3. Pinkie Pie x Cheese Sandwich (unoriginal, I know)  
These two were a couple (almost) immediately. She and Cheese dated for only a few months before marriage. Their business of party planning quickly took off, causing their family to become one of the most wealthy in Equestria. Despite their wealth, both share a room in Sugarcube Corner. They have a son and a daughter who both have joined the family business.
 
4. Twilight x Sunburst  
At first, Sunburst was madly in love with Starlight Glimmer, and Twilight was with Tempest. However, after Starlight began to fall for Trixie, Sunburst decided he wanted to be mature about it and let go. On the other hoof, storms were brewing between Tempest and Twilight, with the fallout ending with a divorce. Through coincidence of meeting up one day, both Twilight and Sunburst used their rare conversations to let out their anger and sadness to each other. Soon, they began to get close. Compared to the rest of her friends, she was second to last to get married.
 
5. Starlight Glimmer x Trixie  
These two had quite the rocky road of a relationship. At first, there were countless arguments between them and were on the brink of divorce. However, after some help from Tempest, the pair began to mend their relationship. Through the help of magic, they had a few foals. Nowadays, Trixie and Starlight are some of the happiest mares in Ponyville.
 
6. Luna x Thorax  
At the beginning, Thorax and Luna got married to help cement good relations between the Changeling Kingdom and Equestria. Luna took frequent trips to Equestria to visit her sister.