It's almost impossible not to start the list with Ajax. Playing in the Eredivise, the Amsterdam-based outfit are level on points with rivals PSV with just two games left in the league campaign, but it's not their league campaign that has grabbed the footballing headlines.
Their remarkable run to the Champions League semi final saw a team of rather inexperienced youngsters knock out holders Real Madrid in the round of 16 after securing a memorable 4-1 win at the Bernabeu, before then doing the same to Cristiano Ronaldo and his Juventus side with a 2-1 comeback win in Turin.
It took a remarkable second half comeback from Tottenham in the semi finals to end Ajax's dream run, but they certainly won the hearts of football fans across the world with their courage throughout and their unique style of play.
The French league title was a foregone conclusion weeks ago with PSG running away with it, but one team in Ligue 1 has emerged as the surprise package this campaign.
Last season Lille survived relegation from the top flight of French football by a mere point. Fast forward one year and the same club have managed to defy the odds and are in great position to secure a second placed finish.
It's been a dream season for Christophe Galtier and his men which has seen them win 20 of their 35 games so far. They are the league's second top scorers behind PSG and amazingly have the league's best defensive record. A brilliant accomplishment for a club who now appear to have been rejuvenated.
In recent seasons Eintracht Frankfurt have been a solid mid-table outfit in the Bundesliga, but this season they really have put their name on the map of European football. With two games left in the Bundesliga season they have the chance to break into the top four, but it was their performances in the Europa League which grabbed the headlines.
After topping their group Frankfurt went on to reach the semi finals after impressive wins over Shakhtar Donetsk, Inter and Benfica, with only a loss to Chelsea on penalties denying Adi Hutter and his men a place in the final.
Regardless of the result it has been a fantastic season for Die Alder and they'll certainly be hoping to keep hold of players like Luka Jovic and Ante Rebic in order to try and progress even further next campaign.
Not much was expected of Atalanta heading into the Serie A season, especially after they managed to win just one of their opening eight league games. However, since then they have gone on a remarkable run which has seen them win 17 games and lose just five times, propelling them all the way up to third in the Serie A standings.
Not only that, but they've also reached the Coppa Italia final after knocking out Juventus and Fiorentina en route. They are now on a 13 match unbeaten run and have won all of their last five games, a remarkable feat for Gian Piero Gasperini's men.
The story of Wolverhampton Wanderers over the last few season has been a remarkable one. After their relegation from the Premier League in 2012, they soon dropped down to League One, seemingly hitting rock bottom. Now, they've turned their fortunes around having secured their return to the top flight of English football last campaign.
It was an impressive feat at the time, but in their first season back in the big time Wolves have secured a seventh placed finish. It's been a fairy tale-like campaign for Nuno Espirito Santo's men which has featured impressive wins against the likes of Arsenal, Manchester United, Chelsea and Tottenham.
They also managed to reach the semi finals of the FA Cup where they were then beaten by Watford, but regardless Wolves have certainly surpassed all expectations this season.
They were relegated from La Liga in 2016 before then securing promotion back to Spain's top flight at the first time of asking in 2017, and in their first season back last campaign Getafe defied the odds and finished eighth.
It was an accomplishment which shocked Spanish football fans, but Getafe have now somehow managed to go even further this campaign. They currently sit in fourth with two games left in the domestic season and are in pole position to secure their place in next season's Champions League for the first time in the club's history.
It's a truly phenomenal feat given they were in the second tier of Spanish football just two seasons ago, and could now be about to beat the likes of Valencia and Sevilla to a fourth placed finish in La Liga.