Last summer I had an early Friday at work. My plan was to just go to the beach and relax with a book and a tub of ice cream, but my fiancé turned up at work unexpectedly with a massive bouquet and a car waiting outside. I had no idea what he had planned, but he basically took me out for lunch (and a sail) on a boat before taking me to the airport. He surprised me with a weekend trip to Paris. Best weekend!
A couple of years ago, on my birthday, my fiancé woke me up really early. I had no idea where we were going, but it ended up being a beautiful morning of having breakfast in a hot air balloon. I had talked about wanting to go on one, so it was a really amazing surprise.
A bit old-fashioned, but I thought it was really romantic of my fiancé to have asked my dad for my hand in marriage before he proposed to me. I'm really, really close to my dad, so his opinions and blessings matter to me a lot.
Lastly, my fiancé is a solicitor, and he regularly featured in various news outlets in my country. On my birthday last year he had a live interview on national TV, and at the end of the interview he said to the hosts "Just before I leave, I hope it's okay that I take a second to wish my fiancé a happy birthday. I feel bad about being away from her on her special night tonight"
I'm a very romantic person myself so I love his gestures, and I love surprising and doing nice things for him as well.