It really does depend on what you want to do with GPS:
* I find "GPS Status" a useful diagnostic tool, and a quick way for force refresh AGPS data.
* I don't have any GPS apps for hiking, geotagging, monitoring my runs, etc, but there are apps for all of this.
* For online search and navigation Google Maps is pretty good, but does have odd failures in its data (I've met a surprising number of places where is has the location of commercial premises incorrect by tens and occasionally hundreds of meters, and these are not things that have moved, just incorrect).
* Nokia's Here maps/navigation works pretty well and is free. Can also work completely offline, including for search and navigation. You do need to exit it when you have finished though, because it will stay live in the background and keep the GPS connection going (which means it doesn't have to re-search for your location when you turn the screen back on or switch back to it, so I'm guessing is a design decision, but could waste power if you are unaware. I've not tested whether it will eventually time out).
* There are a number of Open Street Map based apps out there that can provide offline location, search and even navigation. OSM data can be more detailed and more accurate than Google in many cases, but I could imagine there may be places where it's the other way round. I have a copy of MAPS.ME, which works well offline, but navigation is still quite new (works, but doesn't at the moment provide the "heads up" view of most navigation systems). OSMAND is another popular Open Street Maps based app.
* And as others have said, there are commercial offline navigation apps.
* There are also specialist apps for e.g. tagging where you parked your car, but you can do that type of thing with many of the apps I've mentioned above if you can be bothered (I work on the principle that if I reach the point where I can't remember where I parked I probably shouldn't be driving anyway
).