Created by Havas, the spot, which first aired in 2016, depicts the brothers at the dinner table, before demonstrating how the product works with an animation featuring the brand’s fireman mascot.
It finished at the top of Nielsen’s ranking of TV ads on "net potential impact" score: a combination of how many viewers can remember an ad’s storyline and can also attribute it to the correct brand within 24 hours of seeing it.
Nielsen’s ranking used more than one million survey results and assessed 3,600 ads.
With a score of 67%, Gaviscon was far ahead of the next two, in joint second on 62%.
They were M&Ms spot "Eating in bed", which was created by BBDO New York and dates from 2015, and a 10-second spot for KFC, from Bartle Bogle Hegarty, featuring pieces of chicken tumbling into a bucket.
It is the second year in a row that Gaviscon has topped the chart, as well as the second year M&Ms has featured in the top five.
Two of Amazon’s 2017 Christmas executions made the top ten, with "Last minute Christmas deals" and "Going out" both in joint sixth, alongside spots from Snickers and Skittles.
Samuel Davis, Nielsen’s marketing effectiveness consultant, acknowledged that the chart had mixed implications for champions of highly creative work.
""The purpose of an ad is to generate awareness and the best ads are the ones where viewers can remember both the content of the ad and link it to the brand," he said.
"Gaviscon’s ad, like KFC’s, is not necessarily the funniest ad or most heart-warming, but they both do a great job at sticking in people’s minds and that’s what ads should be about."
He added that humour and novel imagery were common themes among the top ten, especially for the five confectionery brands represented.
"Legacy campaigns, where brands rely on elements from tried and tested creatives, have also performed well with the most effective ads heavily featuring familiar characters and themes," he added.
"All too often we see advertisers move from one creative style to another but the top ads suggests that creating an ‘own-able’ style with strong synergies between executions can produce the best results."