Depends on what you demand.
Many of the brands in the market have the Gravity Sensor and Motion Detection.
Normally, G sensor is for daily driving and Motion Detection is for parking.
Basically, the dash camera needs to connect to your car fuse box in order to get the Motion Detection. It is because the dash camera will not be operating after your engine is off. That's why the camera should better hardwired or you go purchase a power supply kit for supplying electricity to the camera.
In the market, you can find some dash cameras already have secondary battery inside of the black box in order to support the motion detection. Where some don't have it.
Graphic quality is another problem when you are choosing among different choices. Normally like 720p and 1080p are always in the market, you can see brands like Street Guardian, Mini080x series, Lukas, Papago and Thinkware have perfect video quality.
Sizes problem is also an issue for customers while choosing from. You can have a big size, normal or a small size. small size like mini 080x series and papago are all good, but there is other korean brand starts with a "B" in the market where it cannot fix the problem of overheat because the cam is too small. If you don't care about the size, Street Guardian, Thinkware and Lukas can also fit your need. And some of them are with wifi functions too.
The last one is the SD card memory, you will need a big memory card to support many hours of recording. Please don't use cheap SD card in the market, better to stick with the original brand SD card from where you purchase the camera. However, SD cards are expensive if you want to record up to 512 GB. For example, if you are buying a Lukas Dash Cam, I can tell you the 512 GB memory SD card is about $500 Canadian dollars.