They are the clashes that bring entire nations to a standstill, divide cities, turning family members against their own blood, the importance of the final result cannot be quantified because it means much more than silverware. For 90 minutes nothing else matters, but whether you win or lose.

They are the derby matches.

On the back of the Manchester United-Manchester City clash over the weekend ? which predictably ended in controversy ? we take a look at some of football?s biggest derbies.

1. Boca Juniors vs River Plate

The biggest football match in South America and possibly the world. Dubbed ?Superclasico? this intense rivalry does only captures the nation?s undivided attention for 90 minutes, but for days! Boca are traditionally regarded as the club of Argentina?s working class, while River Plate are seen as having the upper-class support base. Recognised throughout the world for its fierce and passionate support, Superclasico is 90 minutes of deafening screams, roars, huge avalanches of standing fans and never-ending fireworks. This is football at its most raw and fluent ? Boca Junior vs River Plate the greatest derby in the world.

Riot Rating: Violence is known to have broken out in nearly every encounter with football gangs overpowering the police on a number of occasions. 8/10

2. Real Madrid vs Barcelona

Although technically not a local derby, when these heavyweights go toe-to-toe Europe and the rest of the world takes notice. Madrid and Barcelona are the largest cities in Spain and are divided by their political past, which only intensifies the spectacle. Real and Barcelona are two of the most influential clubs in world football, and some of the greatest players of all time have graced this fixture - the likes of Alfredo Di Stefano, Zidane, Ronaldo, Messi, Maradona and Ronaldinho making it a footballing feast.

Riot Rating: Despite the fierce rivalry there are minor acts of violence although nothing compared to other derbies. 6/10

3. Glasgow Ranger vs Glasgow Celtic

Mention Scottish football and you will undoubtedly focus on the Old Firm derby. It's one of the most exciting derbies in the world with two of the most successful clubs in Scotland. The green and blue half of Glasgow have monopolized Scottish football for decades claiming a total of 66 Scottish Cups and 93 Scottish Premier League titles between them. Rangers are a Protestant club, while Celtic are considered a Catholic club. The rivalry is so intense that only five players have ever moved between the two teams. The cauldron-like atmosphere at Ibrox and Celtic Park is unrivalled in Britain.

Riot Rating: The Old Firm holds the record for the most aggregate arrests during any derby and is best known for the on pitch fight during a meeting in 1980 at Hampden Park in which 9 000 people were involved. 7/10

4. Millwall vs West Ham

The mayhem that marred last month?s Carling Cup fixture between these two mortal enemies proved to the rest of the world that this is England?s most volatile and ill-tempered clash. The rivalry is made even more special due to the infrequent meetings between to the two sides. The two are based in East London and the sheer hatred between them runs deep, having originated from two rival shipyards across the Thames.

Riot Rating: If the scenes from the last clash between the two proved anything, it?s the realization that the match has now become a straightforward demolition derby, a mass brawl for the hooligans. 10/10

5. AC Milan vs Inter Milan

The most glamourous fixture on the Italian calendar sees arch rivals AC Milan and Inter Milan clash at the San Siro ? a stadium they both call home. AC Milan was formed by a group of English immigrants in 1899 but, citing disapproval at a lack of international personnel, some disgruntled members broke away to form a city rival. A fiercely contested fixture that always delivers controversy and fervour.

Riot Rating: Italians are a hot blooded species, combine this with the intensity of a football derby, and expect fireworks on and off the pitch. 7/10

6. Fenerbache vs Galatasaray

This Istanbul derby involves two of the most successful clubs in Turkey. It literally divides the city into two halves ? Galatasaray on the European side of Istanbul and Fenerbache on the Asian side. This clash is synonymous with fanatical support from both sets of supporters, which frequently boils over there has been no shortage of controversy in the derby with bookings, sending offs and clashes between the two sets of supporters a common thing.

Riot Rating: Acts of violence and hooliganism are common at this fixture. 9/10

7. Manchester City vs Manchester United

As with any major football rivalry, gloating and banter between the two sets of fans is commonplace. United fans love nothing more than to point out that City have gone several decades without winning silverware, but with their newly acquired riches the Manchester derby as taken on added significance now that the blue side of Manchester is seen as a genuine threat. Judging by the tremendous match witnessed over the weekend meetings fans can look forward to great matches in the future.

Riot Rating: Despite there been a great rivalry between supporters they tend to be civilized towards each other. 4/10

8. Roma vs Lazio

The Italians serve up yet another mouthwatering clash, this time it takes place in the eternal city Rome. Both teams hate the arrogance from the Northern teams Inter, Milan and Juventus, but they hate each other more. AS Roma is the team supported in the popular roman districts, while Lazio support hails from the rich Roman districts of the city - the result on the day takes on greater importance than silverware.

Riot Rating: A couple of seasons ago a lengthy battle between both sets of fans and police ensued, stands went up in smoke and people fled the stadium screaming. Eventually over 13 arrests were made and over 170 members of the police were injured. 7/10

9. Liverpool vs Everton

The Merseyside derby has been labelled as ?friendly derby? due to the close proximity of the clubs, but there?s nothing friendly when these teams clash. Families are divided as family members become enemies for 90 minutes. Unlike most derbies violence between Evertonians and Liverpudlians is a rarity but the relationships between supporters have become strained over the years.

Riot Rating: Violent clashes between supporters is rare after all it is dubbed the ?friendly derby?. 2/10

10. Kaizer Chiefs vs Orlando Pirates

Ranked among the top derbies in the world for its passion, history and colour, the derby pits the nation?s most popular teams, Kaizer Chiefs and Orlando Pirates, in a contest that focuses on one-upmanship rather than quality football. The premier fixture in South African football no other match captures the imagination of the public than the Soweto Derby.

Riot Rating: These sets of supporters are not known for their civilized conduct more than happy to voice their frustration if they feel their team is not performing. On the 11 April 2001, 43 Chiefs and Pirates fans were killed when a stampede saw fans of both clubs crushed to death. 7/10