The Decathlon is a well known Print and Play. Part of that is definitely because it's by a well known designer. Part of it is because it's easy to make. Print out a page and grab some dice. But part of it is because the Decathlon is a decent, although not brilliant, game.
As the name flat out states, you play out the ten events of the Olympic Decathlon. The twist is that each game is it's own distinct dice mini-game. And both the strengths and weaknesses of the game are tied to that.
On the one hand, most light dice games are repetitive. You're doing thats same thing over and over again. In the Decathlon, the events are just different enough that you have to adjust your thinking for each event. That gives the game a distinct feel, even after all these years.
And you have a limited number of rerolls in each game. That both keeps the game moving along and keeps the tension high. There is weight to every roll you make.you have to decide how far you want to push your luck.
On the other hand, lets be honest. None of the mini games are strong enough to stand on their own. No one is going to sit down and say let's play a few rounds of the 400 meter dash. The overall game is and has to be greater than the sum of its parts.
(Moving on to neutral elements)
The Decathlon has the odd quality of being pretty dry and pretty thematic at the same time. If the theme was fixing ten parts of a space ship or fighting ten battles of Alexander the Great or operating ten different rail lines, it wouldn't work nearly as well. The Olympic Decathlon gives it a unifying theme that makes each mini-game flow together. But it's still pretty dry.
The Decathlon is also a bit longer than most light dice games. I'd pull out Cinq-O or Zombie Dice if we wanted a quick, low thought activity. The Decathlon is just long enough and (maybe) just complicated enough that it's more of a planned game rather than a spontaneous one.
All in all, Reiner Knizia's Decathlon still holds up. I'll admit some of its value comes from the fact that the files are free and it costs almost nothing in time and materials to make. But that alone doesn't make a game worth playing. It also has tension and interesting decisions to make. It's not perfect and I wouldn't want to play it every week. But it is a game I'd play again.