What you want/need the weapon to do will steer my recommendations in a big way.
If you want something for formal target shooting, the SIG (in the steel-framed single-action-only version with a nice trigger job) is the way to go.
For a range blaster/toy, any of them will do. Pick the one you like best based on looks/feel.
For more serious uses, the field narrows quickly. Unless required by administrative policy or regulations, I simply will not recommend a DA/SA (long/heavy double-action for the first shot, shorter/lighter single-action for all subsequent shots) autoloader any longer. I no longer believe there is any objective reason to select a DA/SA auto over any of the higher quality weapons that have a single trigger pull action/weight. Whether it is a true Single Action, a similar striker-fired action like Glock's Safe Action, a Double-Action-Only long-pull weapon, or something in-between, there is no longer any practical reason to struggle to learn and execute two different trigger pull weights/lengths/feels. Based on this, the conventional SIG and HK DA/SA autos are out of the running, in my book.
I once would have chosen the .45 XD over any Glock in the same caliber, based solely on the size/circumference of the grip frame, despite otherwise being a rather strong advocate of Glocks, in general. Once I laid hands on a G21SF with it's improved ergonomics, I no longer have to recommend against the reliable and easy-to-use Glock in .45 ACP for any reason. In its G21SF form, it is slightly smaller than the largest of the XDs in .45, so if concealed carry is a possibility, then the Glock should be your choice. For open carry only, then the XD is still in the running, but I personally can't see anything that would push me to recommend it over the Glock.
"Placement is power" -- seen in an article by Stephen A. Camp
(RIP, Mr. Camp; you will be remembered, and missed)