A lot of people ask "What mods should I get?" and Better Heads is usually mentioned. I don't care for Better Heads, and think there are much better head replacer mods out there.
Here is a link to a post that links to some of the original NPC heads, and the way those same characters look in eight different mods, including Better Heads. (My favorite is #8) Have a look and decide for yourself.
Still think BH is the best, I'm honestly quite surprised how many of them screwed up with the census dude and Fargoth. Anyways, Emma's heads deserve a mention, they're not mainly for NPC use but they're available for a couple towns, at least...
Link: http://lovkullen.net/Emma/faces.htm --- ANYBODY WHO HAS EVER DISPLAYED ANY EMOTION OTHER THAN HAPPINESS, LOVE, AND BOREDOM IS EMO. I KNOW BECAUSE THE INTERNET TOLD ME.-observer1258