The Millers, who are chasing back-to-back promotions, put in an inspired display to see off favourites Preston, with goals from Wes Thomas, Lee Frecklington and Kieran Agard overturning Paul Gallagher's early opener and sealing a final date with Leyton Orient at Wembley.
It was a trademark display of attacking endeavour, orchestrated by the influential Ben Pringle, which could have yielded a bigger winning margin but Evans was still left beaming.
"It feels wonderful, when we came up into League One we were people's favourites to go back down but we worked hard and we have had a fantastic season," the Scot said.
"Over the two games we deserved it, it's a great night for us.
"When we went in front I knew we would win, when we scored the third I thought we might go on and win very comfortably.
"I have had some magical highlights and it will be a very proud moment to walk out at Wembley.
"This ranks right up there, I still maintain that the Aldershot game last year is still the best because we won promotion, but this is up there."
Rotherham will meet Russell Slade's Orient, who led the division for much of the campaign, at Wembley and Evans expects another titanic clash.
"It's my job to make sure everyone enjoys the moment but we will start preparing for Leyton Orient tomorrow," he added. "We will be underdogs when we get to Wembley we know that, they have been top of the league for most of the season.
"We have taken ourselves to the final fence but that is the size of Becher's Brook when you look at the opposition. If I could emulate what some other Scottish managers have done at Wembley I will be happy."