It's safe to say that Christmas 2018 was a success for the Heck household.

Our son Grayson is 5, going on 6 years old and, for the first time, he was 100 percent all-in on the big day this year. From tree lightings, to seeing Santa Claus as many times as possible, to taking in all of the holiday programming he could handle -- he was at the peak of excitement this year.

Grayson has been a fan of Thomas the Train for as long as my wife and I can remember. There was a point, however, where it seemed he had moved on to other things that interested him. But as most kids do, they throw you for a loop. When it seemed like his days of being a Thomas enthusiast had been behind him, suddenly, he was back on the train -- pun intended.

He started watching videos on YouTube of people unboxing and playing with a Lionel G-Scale Thomas the Train set. From that point on, it was his mission to ask Santa Claus, every chance he could, for that particular train set. My wife Holly had searched far and wide, and after going on eBay, she finally found the one he was looking for -- which happened to be a set that was put on the market back in 1993.

Now, as most 5-year-olds can be, he had his ups and downs heading into the holiday season, but we knew Grayson's heart was always where it needed to be. So we decided to make the train set a surprise. Santa brought Grayson's presents and put them under the tree -- with the exception of THE ONE. He opened them all up and he was so humbled to have received them. He was happy, sporting a smile from ear to ear. When it seemed like all gifts were unwrapped, my wife asked him if he got everything he had asked for. His response was "yes." As a father, the way he responded to everything -- considering how many times he had asked for that train set -- was pretty amazing.

Then, it was time to unleash the surprise. His response was the best Christmas present I have ever received. Check it out below:

Tell us your stories of how you surprised your child for the holidays in an unforgettable way.