These 4 Swedes hit it big in 1974, when they won the Eurovision Song Contest, with "Waterloo". Since then they've been one of the most successful music groups of all time. Now they may have had only one #1 single (Dancing Queen) in the US, but look at how many they had in other countries (they were very popular in Europe and Australia). America would really be considered they're only failure (if you want to look at it that way), but they were still popular enough in the US to get at least 3 of their albums RIAA certified gold and one RIAA certified platinum!