I get asked this periodically - as I'm sure many photographers get asked all the time. And the simplest answer is - the one you've got with you. For most people, its their smartphone.

But, for those of us that want an actual separate physical camera for the best quality may want to consider what I feel is the best pocket travel digital camera overall: Sony DSC-RX100M II.

Why is it the best overall for me and many people?

fits in my pocket, so I can take it everywhere with me
1" sensor size is so drastically bigger than typical pocketable point and shoot cameras = highest quality
best image quality in its class
has an intelligent hot-shoe so I can use my powerful flash guns if I wanted
intelligent hot-shoe so I can add other Sony accessories
images can be transferred via wifi to my smart phone and uploaded / shared on the go
fantastic low light image quality
sony has best image stabilization
fast lens with wide aperture starting at 1.8
20.2 megapixels!

For those of you that want something even more portable - consider the Sony DSC-QX100 Smartphone Attachable Lens-style Camera. Its built with the same guts as the RX100 II, just minus the non-essentials that you can substitute with your smartphone.

A better deal is the Sony RX100 which was just released last year and offers almost as good image quality. You lose out on the flip/tilt screen, hotshoe, wifi, nfc, and slightly lower image quality in low light. Still, its an amazing camera.