What camera is best for photography, travelling, filming, out of these?

Samsung NX500
Sony A5100
Canon EOS M3
Canon G7X

Samsung are still trying to live down a bad (and not entirely undeserved) reputation, and are rumoured to be getting out of the camera business, I'd avoid them.

Sony are the big boys in EVIL (their sensors are so good, Pentax and Nikon buy them for their DSLRs), and I'd take a proven and popular Sony over Canon in this field (Canon's DSLRs are good, but they've lurched from crisis to disaster in their EVIL models).

The Canon G7X is a superb compact, but it competes directly with EVIL models in price, while having a fixed lens, a smaller sensor, and not being that much smaller in size than its more capable competitors.

From your list, I'd take the Sony without hesitation. I only have experience with the G7X use it for travel photos and videos mostly. I've been very happy with it. It produces top quality results. I particularly like the 100mm zoom lens, the touch LCD screen, and the large 1" sensor.

It's easy enough to research and compare the specs on all these cameras but specs don't tell you everything. Unfortunately, I doubt you'll find anyone here who has had experience with all these cameras. If I were you I would go to web sites such as B&H Photo and Amazon and read the actual owner reviews on each camera. Any.

They're all good cameras along with all other mirrorless cameras out there. Just bear in mind that in photography, you get exactly what you pay for.

I only have experience with the G7X use it for travel photos and videos mostly. I've been very happy with it. It produces top quality results. I particularly like the 100mm zoom lens, the touch LCD screen, and the large 1" sensor.

It's easy enough to research and compare the specs on all these cameras but specs don't tell you everything. Unfortunately, I doubt you'll find anyone here who has had experience with all these cameras. If I were you I would go to web sites such as B&H Photo and Amazon and read the actual owner reviews on each camera.

Any.

They're all good cameras along with all other mirrorless cameras out there. Just bear in mind that in photography, you get exactly what you pay for.