Paul Anka's biggest "hit" or at least the most played may well be the theme tune for the Johnny Carson show. He wrote it as a favour when Carson was unknown. Great artist or another time, and a gent.
My Way is his most famous song, but Diana sold bucketloads. It Doesn't Matter Anymore, wasn't that big a hit initially, but had the "fortune" of being the one that was out when Holly died, which is the only reason it was a bigger hit.
Puppy Love must be close to being his biggest hit, Donny Osmond reached number one in the UK, Canada and Australia and number 3 in the US in 1972 with it.