The Eagles and the Hornets have overachieved massively to get to this point but there is real spirit and togetherness about both teams and they have fully deserved to get to Wembley for Monday's monumental showdown.
The nerves will be jangling amongst the two sets of fans but I think the game will be enticing to the neutrals, too, because Palace and Watford only know one way to play - and that's to go forward and express themselves.
Palace managed to keep a couple of clean sheets against Brighton in their semi-final victory, though, and also put in a very high level of performance, so they should be ridiculously confident ahead of the meeting with Watford.
And they will have even more belief if the extremely talented Wilfried Zaha shakes off an ankle knock to take his place in the side, because he is a match-winner of the highest calibre, as proved by the princely sum Man United paid for him.
The winger took a while to get into his stride against Brighton but soon showed his willingness to take on his man and get crosses in and you could see what it meant to him to score two goals and fire Palace to Wembley.
He will feel it is his destiny to join Man United in the summer in a blaze of glory by taking Palace into the Premier League with him, and I would expect him to start, even if he has to take a pain-killing injection.
Zaha will be the Eagles' chief threat but the two nightclub bouncers in the middle of the park, Mile Jedinak and Kagisho Dikgacoi, as solid a band of brothers as you can find, will keep Palace on an even keel.
The Londoners' fans may play a key role as well; I hate the logistics of going to Palace as it takes a five-day camel ride to get there, but I love the supporters who are really something else with their non-stop passion.
However, I just fear that without the injured Glenn Murray up top, the Eagles could be short of firepower; Aaron Wibraham is a physical presence and an accomplished player with his back to goal but he is not a goalscorer.
A lot of column inches have been devoted to Watford's extensive use of the loan system - which Palace boss Ian Holloway has been particularly critical of - with the Hornets exploiting a loophole to acquire a plethora of players from Italian outfit Udinese and Spanish club Granada.
However, no rules have been broken and Gianfranco Zola cannot be praised enough for uniting nations, getting his team playing a fantastic brand of football, and fostering character amongst the group, which was evident in spades as they saw off Leicester in such dramatic, and late, style.
The Hertfordshire side also have goal getters from all angles; Matej Vydra won the Championship Player of the Season award but fellow frontman Troy Deeney has been inspirational and brings a strength and reliability to Watford's slick football.
The one-time Walsall man netted that immortal goal to down Leicester but Ikechi Anya showed a sublime touch to set his pal up and he has assisted so much this year with his constant supply line from the flanks.
I have been so impressed by the way Watford's foreign legion, who are not used to playing regular first-team football, have settled into the war of attrition that is the Championship and the Saturday-Tuesday-Saturday regime.
Monday afternoon's contest will be the biggest test of all, though, and it is probably the hardest of the three play-off finals to call because there are plenty of game changers on both sides.
The winners will earn a reported a £120million - and I expect Watford to be the ones lining their pockets.