I can only comment on Stargate. I bought this a year and a half ago, and you cannot appreciate it until the flippers work properly, and the game is dialed in. It also has to be set up kinda steep.
The good thing about SG is that the ruleset is deep, but easily followed. It is a game that you eventually just know how to play, and what you need to do, and can judge shots at a glance. That doesn't mean you'll make the shots, but you'll know what you need to do.
The shots are rewarding, and some are difficult. Yes, it has a ton of multiball modes, but that's worked into the rules, and it becomes part of the game. You need to do more on the multiballs to get the big numbers than just obtain the multiball modes. The game IS NOT a flow game. If you like that, then SG won't be for you. I like this type of game, so it will be with me a long time, and I personally like a lot on the lower playfield to shoot at. I don't consider that cluttered.
We also have a WOZ, which is also not a "flow game" per se. And since WOZ is new, it gets a good bit more play time than SG. However, to me, playing a good game of SG is just a thrill. I don't get tired of it, and enjoy it easily as much as playing WOZ or any other pin.
The game also follows the movie pretty well, if that means anything to anyone. And, it appears to be a pin that can be bought right at this point.
There are many games out there to pick from, so find what best fits your needs as far as game play, theme, etc. I never liked the theme on Congo, and I am still looking for a Shadow to play. I've heard it is really good.