This season, some of the sides that have proved the most-difficult to beat might just surprise you. Where normally it would be expected to see the usual suspects; perhaps Barcelona, Juventus and Paris-Saint Germain, this time around things have been slightly different. The aforementioned clubs are not even in the top seven, and while the likes of Bayern Munich and Real Madrid are included, there are a few names that not many would have predicted to be so consistent... Arguably the most...
Hoffenheim coach Julian Nagelsmann has earned numerous plaudits this season, and deservedly so.
The 29-year-old (yes, 29) has led Hoffenheim into fourth place, and potentially their first ever inclusion in the Champions League, playing high pressing, energetic football that has certainly caught the eye.
Die Kraichgauer have proven to be extremely tough opposition, beaten only by RB Leipzig, Wolfsburg and Hamburg. Even more impressively, they were undefeated in the Bundesliga until the end of January.
They have, however, drawn more than any other side in the division, 13 of their 30 games ending in stalemate.
Tottenham were beaten by Chelsea in the FA Cup semi-final on Saturday, but in the league they have been in imperious form.
Mauricio Pochettino's side have lost only three Premier League games, beaten by Chelsea, Liverpool and Manchester United away from home. They are a formidable prospect at White Hart Lane, and now just four points off Chelsea at the top, cannot be ruled out of the title race just yet.
They may just have to avoid defeat for the remainder of the season if they are to catch Chelsea, however.
Jose Mourinho and his side have had their critics this season, and at times it has very much been a tumultuous campaign.
Regardless of the much discussed issues, it's undeniable that United have proved extremely difficult to beat. Like Hoffenheim, a plethora of draws have prevented Mourinho's side from challenging at the top, and it's something they will be looking to address next season.
A solid defence, the second best in the Premier League, has ensured that defeats have been a rare occurrence, although 48 goals scored is considerably fewer than all other sides in the top seven.
Monaco are very much one of Europe's surprise packages this season.
Leonardo Jardim's side booked their place in the Champions League semi-final with victory over Borussia Dortmund last week, and remain on course to lift the Ligue 1 title.
PSG currently top the table, although Monaco, three points behind, have two games in hand. Having scored an incredible 90 goals so far, and been defeated on just three occasions, they will be expecting to regain their place at the top.
Zinedine Zidane has introduced a ruthless efficiency to accompany the flair at Real Madrid this season.
Los Blancos have only been defeated twice in La Liga, and if that remains the case after Sunday's El Clasico, the title will be within touching distance. A potential league and Champions League double remains on the cards after last week's somewhat controversial win over Bayern, and there's a feeling of assured self-confidence about this squad.
Only Valencia and Sevilla have been able to stop them as yet in La Liga. Barcelona will be desperately hoping to change that.
Perhaps not overly surprising given their dominance of the Bundesliga in recent years, but Bayern have been as imperious as ever domestically under Carlo Ancelotti this season.
The aforementioned Hoffenheim did inflict a rare defeat, their second of the season, earlier this month, and Mainz came close to producing a shock result on Saturday only to draw 2-2.
Rivals Borussia Dortmund are the only other side that have beaten Bayern, winning 1-0 at the Westfalenstadion in November last year.
Arguably the most surprising of all the teams is Ligue 1 side Nice who have lost just twice this season!
The additions of Dante and Mario Balotelli in the summer suggested ambition, and that has certainly been the case. Lucien Favre's side have kept pace with Monaco and PSG at the top and are still not yet completely out of contention in the title race with five games remaining.
Lowly Caen inflicted defeat on Nice in November last year, while Monaco secured a crucial 3-0 win against their title rivals at the Stade Louis II in February.