Sweden has won Eurovision 6 times which is the 2nd most wins as of 2020, the first being Ireland with 7 wins. One of the Swedish winners is the band ABBA which became popular worldwide after their win with the song "Waterloo".

Greece has won only once in 2005 with Helena Paparizou and her song "My number one". She competed in Eurovision before that in 2002 as a part of the duo "Antique" as the lead singer.

Switzerland has won twice so far - in 1956 , which is the first year that Eurovision was held. The country won on their home territory since it was hosted in Switzerland. There is a bit of conspiracy with their win in 1956 because no one actually knows how the exact voting went but the official winner is Switzerland's Lys Assia - "Refrain". They also won in 1988 with Cèline Dion and her song "Ne Partez Pas Sans Moi" (Don't leave without me). After the contest Celine became the worldwide known singer we all know and love today. Her most popular song is "My heart will go on" from the movie "Titanic".

Poland on the other hand has never actually won the contest. Their best result is 2nd place in 1994 with Edyta Górniak's song "To nie ja". In translation the title means "This is me". That year is Poland's debut year so that makes it quite special that they came 2nd. The best ever result for a debuting country is Serbia's "Moltiva" (Prayer) which came 1st in 2007.

More Info: en.m.wikipedia.org