We tend to use iPhone apps of TomTom or as others have said Sygic is also a very good option. Sygic has HUD, Dashcam, Photo Navigation and such (sometimes free, sometimes addons) and a worldwide map version (available at sale prices sometimes).
While stand-alone SatNavs have some better features such as ability to add planning and routes before the trip, TomTom completely lost me for their devices when they wanted to charge me $149 for a new world map one month after I had purchased one of their XL machines some years ago. Plus you have to take and keep secure another physical device, power supply and mount. Phone mounts plus cigar lighter or direct USB connection to car these days are $5 from Australia Post and elsewhere. It's a pain to have to remove the SatNav device from the car when you park it while one always takes the phone.
While stand-alones now seem to have more sane map upgrade policies, iPhone apps (currently) have free lifetime map upgrades. For TomTom, we use the traditional iPhone app not the new one - which seems to me like an attempt to rip off users with yearly fees, and it just doesn't work (for me) as well as the main app or Sygic.