I had never heard of these guys (163 Ang Mo Kio Avenue 4 #01-446, 6458-7374), but apparently their charcoal-grilled bak kwa is in such high demand that it's difficult to get on the waiting list for it. And it is pretty good, with its very tender and mildly smoky meat.
If you do not want to queue for hours during the Chinese New Year, this particular family-owned bak kwa shop is definitely a good alternative but do order earlier to avoid disappointment.