Alright so with two of my characters, my Orc and my Breton, I have been to Riften and got the Amulet of Mara, and donned it while in towns and cities. I have done the first mission for the temple, helping a couple to elope. Still nobody has shown any interest.

I know the whole marriage thing is just a gimmick but hey, its in the game and my characters want a traditional lifestyle outside of work.

So after weeks of frustration I'm finally asking you guys. What am I doing wrong in game?
It seems I'm the only player who can't get married.

First of all, there is a finite list of people who are available for marriage. Second, in order for them to be interested in you, you have to first do a quest for that person (in a few cases, you have to complete a series of quests). Here's an explanation: http://www.uesp.net/wiki/Skyrim:Marriage

Thank you this is a great help!