This is as close as it comes to a tie for me. Shadow's theme doesn't appeal to me as I like Whitewater's more fun and light heartedness. Like Big Foot and the ramps are fun. However, I like the game play of Shadow just a tad better as I just like it's unique shots, the battlefield, and some other things. Whitewater used to be much less expensive but has risen in price a whole lot the last 2-3 years. Possibly if you get one it will increase later but then again some say it has gone as high as it's likely to go and may even go down in price, but who knows anymore what prcies on pins will do?! Many say Shadow would cost way more except many dislike the theme and artwork, especially Alec B. Having watched thepretty lame, I find the theme, quotes, and movie very well integrated and don't mind the BG near as much, but there are alterative BG's. Gosh I guess it might come down to if I saw both machines for sale and couldn't afford or didn't have room for both, cost and condition of each machine could be the deciding factor. I will say that a Shadow that's not be well maintained or dialed in right can have minor but annoying issues such as switches that don't register and other things that do impact game play. Make sure when the balls are locked that when you get mutli-ball the balls exit properly. If the switches don't register properly they won't and it's really annoying
In the end, both are very, very good games and hard to really recommend one over the other for me. If you can, play both and if you really can, get both-ha! Full disclosure, I own a Shadow and so am a little biased but have been real close to getting a Whitewater and find it a quite fun game.