I was a GPS junkie for a while, so here we go...
Sygic is the best Android GPS app. How the maps scroll and pinch and zoom makes other GPS programs look like they're 10 years old. It's just... smooth and colorful. The last update added a lot of minor fixes. About the only thing that annoys me on it is I can't make it warn me earlier than 1/2-mile before the next turn. Kind of important if doing 80mph on the highway. ..Hmm, or maybe the latest update did add that. I'd have to look.
CoPilot is great, and not just "for the price." The free version has limitations such as no voice guidance, and 2D maps only, (I rarely used 3D maps anyway), but what do you expect for free. Everyone who uses Google or other needs-data maps should put a copy of the free CoPilot (or some other free GPS, I guess) on their phone for a backup.
I'm rather impressed with the paid version of CoPilot. And it's very inexpensive. A main complaint of it over the years has been the map updates were lacking, missing newer roads and turns, etc, but I used it on my last big trip and didn't notice that. ymmv.
CoPilot even had drag route capability before Sygic recently added it. I don't know if any other GPS programs have that. I don't think they do unless they were very recently added. Really nice not to have to add waypoints to force it to use a specific road or turn when planning a trip.
A negative for coPilot is it was slowly draining my battery even when plugged in and even with battery saving mode on. Drained slowly, like 10% every hour if that, (maybe less, I forget), so not a big deal for most people and most trips, but it's still a negative. I think I read the newest version fixed that, but I haven't used it in the past few months.
TomTom. I hate the map on it. Pinch zoom only, which is fine if it was smooth, but it's not smooth at all, at least when I used it six months or so ago. The maps themselves are ok, and if I recall it has a really nice list of POIs, but every time I had to touch the map I hated it. Maybe it's better now. Oh, one big negative: IT CAN'T SAVE ROUTES. I even did an internet search on TomToms of various kinds, and lots of people complained how their TomToms can't save routes. Crazy. Can ANY TomTom save routes? If it can, I couldn't figure it out. It does have some weird "set a time" thing for routes. Whatever, it annoyed me. Thumbs-down. :thumbsdown:
Navigon's maps are in second place behind Sygic's to me for looks, and I like how POIs can be specific icons, but it can be frustrating to use. I think I read the iPhone version is really good but the Android version is different and bad. I just know it's not all that intuitive when it comes to preplanning routes, I think switching between 2D and 3D required going into multiple menus, it's just annoying. Once the route is in it, it's good though. Good voice and turn guidance and things. If memory serves, it basically only has one volume level: loud. I've seen others say it's too quiet. I think a decent volume control is one of those things the Android version is missing.
Really, they pretty much all have good voice guidance, and I could probably find specific faults with each one if I used them again right now, but I singled out Sygic's early-warning thing because I've used that the most and it's probably the only thing on it that annoys me enough to think of right now.
Things like NavFree are ok, in fact, it surprised me how nice it is, but the maps were lacking around me when I was away from major areas. It's free though, so give it a try. I've tried various other GPS too but found them lacking enough that I can't think of them right now. Or that they didn't store the maps on the phone. I don't recall trying the one mentioned in the second post. I'll have to give it a shot.
To sum up for the ones I've tried: I think Sygic is the best. CoPilot paid isn't far behind at all, some people may actually prefer it, and for the price it's outstanding (unless you run into any bad map problems which I have not but other people have complained about at least in the past). And then there's CoPilot free with no voice and no some other options, and NavFree and others that are free and do have voice. As long as CoPilot paid is the price it is, it's really hard to recommend anything else, even Sygic.