Well you're after unique marriage proposals, so you'll have no problem with me telling you that the best marriage proposals are ones that are unique to your relationship and not ones that are copied from elsewhere.
So if you go with any of the following unique marriage proposals, please make sure you make them your own!
1. Take her to a fancy restaurant and surprise her by being collected in a horse drawn carriage. Drink champagne while you ride around town, cuddle and propose under the stars.
2. Create a candlelit pathway while she's away and have it lead up to her front door! The path then carries on into her bedroom where she finds you down on one knee wearing a tux with a ring in your hand.
3. Take her blindfolded to an idyllic location that is special to the two of you! When you uncover her eyes, she finds that you've made a picnic with all her favourite food. You could have planted some champagne in some nearby water! Propose while you listen to your special song!
4. Recreate your first date! Take a walk past the spot where you first met. Cook the first meal you ever made for her and eat it at your first ever picnic spot. Propose while you listen to the first song you made love to!
5. Collect her from work in a rented limo and drive to the best restaurant in town. Hand her a red rose and make sure you have her best outfit for her to wear. Have them serve you dinner in the limo and you can propose for desert with romantic music playing.
6. Tell her to meet you in the park at lunchtime. Hire a suit of armour and a horse and arrive a few minutes late as her knight in shining armour. Your friend could be nearby ready to play Holst's "Jupiter" as you arrive in the distance. Swing down from the horse and offer to be her prince.
7. Mail her a romantic poem with a photo of you down on one knee! Wait outside for the mail to arrive and when you hear her scream, knock on the door and be on one knee when the door opens!