UK Master’s are looked upon fondly by research institutions/top schools in the US. This is partially because they are, as has been stated, programs that emphasize a research component, but any sort of “study abroad” experience is highly valued because it shows that you make a conscious effort to culture yourself.
When I did my first Master’s in English (which I’m currently finishing), I applied to a bunch of UK schools, was admitted, but couldn’t go because of funding. This time around, though, I’m likely doing a second MA in Film Studies from a UK university and was able to get a good chunk of my tuition covered--so it is possible
Overall, though, UK masters are looked upon very fondly by PhD adcomms.