A while back I was in the same boat as a lot of people here; really wanted the protection a dashcam provides when needed. At the time I was torn between the latest BlackVue and ThinkWare cameras. They seem to be the top sellers as far as higher quality camera systems go. In the end I found a group buy and got the BlackVue DR750S 2-channel system. It was a bit of a pain to install in my WJ because of the lift gate, but super easy to install everything else.
Pros:
- front and rear cameras synced
- 1080p video in both cameras
- enhanced night vision mode
- can get an optional Powerbank that lets you set how long parking mode is online (infinite, battery voltage, time)
- low profile; don't need another screen on my dashboard
Cons:
- price; even with the group buy it was $300+ including SD card
- software isn't the greatest, can be a bit annoying to download footage
- proprietary (or very limited) options for SD cards
For a lot of gadget decisions I like to hit up The Wirecutter and see what their reviews say. Here's their write up on dash cams:
https://thewirecutter.com/reviews/best-dash-cam/