Whether it be a fiercely fought local rivalry or a fixture between two sides gunning for domestic glory, derby matches are great for the game.
Ahead of this weekend's clash between Portuguese giants Benfica and Porto, we look at the top 10 European inter-city rivalries.
From Madrid to Manchester, Rome to Rotterdam, these are the matches that come with the highest stakes, most hardcore fans and, of course, the biggest bragging rights.
The two Ligue 1 sides have faced each other a vast number of times down the years, but only in the last 12 months has the fixture come to the fore. Coined “El Cashico” by the Daily Mail, the fixture now sees two of world football's richest sides contest a match that boasts some of the sport's best players.
Monaco had been in French football wilderness during recent seasons and were forced to spend time in the second tier, but a cash influx from Russian billionaire Dmitry Rybolovlev enabled them to secure promotion and attract some of the world's most talented footballers including Radamel Falcao—though the lure of living in a tax haven surely had something to do with it.
PSG, on the other hand, are one of Ligue 1's best clubs, though they, too, are now among the world's richest outfits thanks to a takeover by the Qatar Investment Authority.
With seemingly endless amounts of cash which, in turn, enables the two sides to attract stars such as Zlatan Ibrahimovic, Edinson Cavani and the aforementioned Falcao, this rivalry will only get bigger.
The Eternal derby, or Croatian derby as it is also known, sees the country's two most popular teams battle it out.
As well as being the two most popular clubs in Croatia, they are also the two most successful outfits in the country's history.
Due to various formats in Croatian football, the two sides can face each other between three and six times per season, making the fixture one of the most-played rivalries in the football calendar.
As with a lot of rivalries, there is animosity between the two sets of fans—something which can often bubble over into hatred.
The Eternal Derby is often overshadowed by fan trouble and violence.
It may be a relatively new rivalry, but Der Klassiker has started to intensify over recent years—gathering more pace and more fanfare.
Historically, Bayern Munich have been the biggest and most successful club in German football history, and are one of Europe's superpowers. With a record haul of Bundesliga, cup, League Cup and Supercup trophies, and with five European Cups to their name, Bayern have, for a long time, been referred to as one of the best clubs on the continent.
Dortmund, on the other hand, have had relative success in domestic football and do have a European Cup trophy to their name, but their honours list pales into insignificance compared to the Bavarian club's.
Despite the history, however, the rivalry continues to intensify due to Dortmund's rise to power in recent years. The two are now serious rivals in terms of fighting for trophies and contested last season's Champions League final, though Bayern had the last laugh with a 2-1 victory.
The Derby d'Italia is easily the most intense match in Italy between two sides from different cities. Though Juventus contest the oldest derby in Italian football history, with their neighbours Torino, and Inter battle it out with AC Milan, who share the same stadium, the Derby d'Italia attracts the most attention due to the number of factors attached to it.
First and foremost it is a regional rivalry, with the two sides hailing from the two biggest cities in Italy—Turin and Milan. And secondly, the two teams are ranked first and second in terms of wins and goals in Serie A.
The Old Lady are one of the most decorated outfits in European football history, with a host of domestic and European successes under their belt and heavily outweigh Inter's 67 wins of the Derby d'Italia with a whopping 94 victories.
As with many derbies, the rivalry between the two clubs, Newcastle and Sunderland, precedes anything related to football. A political rivalry between the two cities, which are just miles apart, continued with the birth of the two football clubs.
The Tyne and Wear clubs are not considered among English top flight's most successful clubs, but the clash can rival that of most inter-city derbies in European football.
Throughout the two cities football is considered a religion, with both outfits boasting huge stadiums and an incredible number of hardcore fans.
The Magpies honours list swamps that of Sunderland's, but, during the 146 meeting, Newcastle shade the head-to-head with 53 wins to their rivals' 45.
The Revierderby, or the Ruhr derby, is the most famous derby in German football. Though Dortmund's nearest rivals—in terms of competing for trophies—is Bayern Munich, there's no escaping the intensity of their clash with Schalke.
The rivalry is so intense because of the clubs' location. Despite being in different cities, they are in the same region of Germany—the Revier—and the clash between the two has always been feisty.
The derby was born in 1925 and has been played 138 times since, with Schalke edging their rivals with 57 wins to Dortmund's 48, but with Dortmund's recent successes, it's hard to imagine Die Schwarzgelben not catching up in the future.
O Classico sees the two biggest clubs in Portuguese football, from the two biggest cities in Portugal, face each other.
The two giants have nine European successes between them and, along with Sporting Lisbon, battle it out for the four domestic titles on a regular basis.
Traditionally, Benfica were the league's strongest side and, for years, had a better head-to-head record over their most fierce rivals. But, during the recent years, Porto have caught up with Benfica and have now surpassed them.
The two sides have faced each other 227 times, with Benfica winning 85 to Porto's 87.
Often referred to as the North-West derby, the fixture between Manchester United and Liverpool is one of the most significant rivalries in world football.
The two clubs are English football's most decorated teams and have contested for trophies—most notably the first division/Premier League—since it's inauguration.
The two clubs have nearer rivals, in Manchester City and Everton, but there's nothing quite like the tension between the two sides—especially their fans when the two clash throughout the year.
Throughout the 70s and 80s, Liverpool were one of the best clubs in Europe and surpassed Manchester United's haul of league titles. A slump throughout the 90s and 00s, however, allowed for United to claw their way back into contention with the Reds.
Despite that, Liverpool fans continually held a sign stating “come back when you have 19,” referring to their side's tally of 18, in the hope of taunting the United fans.
However, it was the Red Devils that had the last laugh as they claimed their 19th league title during the 2010/11 season.
De Klassieker is The Netherlands' biggest rivalry and is one of Europe's most fierce derbies—particularly among fans.
With Ajax hailing from Amsterdam and Feyenoord in the neighbouring Rotterdam, the two clubs have been battling for the Eredivisie, the Dutch Cup and bragging rights since 1921.
Ajax, one of European football's giants, have the edge over their nearest rivals, and with the likes of Johan Cruyff et al. having played for de Joden, have always played a brand of more attractive and free-flowing football.
The fixture, which is usually of the highest quality, can often be overshadowed by the violence between fans before and after the game.
El Clasico is undoubtedly the biggest rivalry in European football. It's one of the most fierce derbies in world football, for that matter. The two Spanish giants, Real Madrid and Barcelona, have for many years competed for major European trophies and are considered as two of the biggest and best clubs on the continents.
The Galacticos' list of honours outweighs that of their greatest rivals, but Barcelona's meteoric rise to prominence over the past decade has seen the rivalry escalate to new heights.
With differing philosophies, differing viewpoints among fans and and world football's two greatest players on opposing sides, the rivalry will only continue to intensify.