In the end, it's possible that the BP Deepwater Horizon oil spill in the Gulf of Mexico will likely to be the most expensive oil spill to date. Indeed, there are estimates that the spill will cost anywhere between $15 billion and $40 billion - with some estimates reaching more than $100 billion.

While the BP spill, which started on April 20, 2010 and still has not been fully contained, will probably be the most expensive oil spill of all time, there are plenty of other oil spills that have cost a pretty penny. Here are some of the most expensive oil spills to date:

Exxon Valdez oil spill: $3.8 billion One of the most notorious and expensive oil spills in history is the Exxon Valdez spill took place on March 23, 1989 in Prince William Sound, Alaska. It gushed about 250,000 barrels of oil, and there have been numerous lawsuits against Exxon in the intervening two decades. Originally, Exxon was required to pay $2.5 billion in damages, but a 2008 U.S. Supreme Court ruling reduced that number to a little over $500 million. Many believe that the cost to Exxon exceeded just the punitive settlement. The spill tarnished the company's reputation and most of its oil shipping is now done by a subsidiary with a different name.

Amoco Cadiz oil spill: $3 billion Another devastating spill was caused by the Amoco Cadiz, a tanker that wrecked during a violent storm off the coast of France in 1978. The violent waves carried the oil far and wide. It was the most devastating oil spill up to that date. Some put the inflation adjusted cost at $3 billion (at the time the cost was closer to $85 million), and regard the damage to the beautiful coast and wildlife as priceless.

Prestige oil spill: $2.8 billion On Nov. 13, 2002, the oil tanker Prestige sank off the coast of Spain. The original reports estimated that it spilled roughly 17,000 tons of fuel. It was later revealed that the actual amount was closer to 77,000 tons. The Spanish government was criticized for failing to report the leak more accurately.

Ixtoc I oil spill: $1.5 billion It took 10 months to stop the flow of oil into the Gulf of Mexico from the 1979 Ixtoc I oil spill. This oil spill's costs have not been fully accounted for, but estimates put the inflation adjusted cost at around $1.5 billion. Although the spill leaked roughly 140 million gallons, the costs were lower than some might expect because the spill occurred outside the United States, resulting in less pressure to engage in extensive clean up and reparations.

Persian Gulf oil spills: $540 million During the Persian Gulf War in 1991, Iraq allowed for the opening of valves on the Sea Island oil rig and dumped oil from tankers into the water - as troops fled Kuwait ahead of the U.S. invasion. The Iraqi government claimed the move was a military tactic, designed to slow American troops down. It's estimated that 1.5 million tons of oil were spilled into the Persian Gulf intentionally. The $540 million is an estimate, but no one knows how much the Saudis, who took responsibility for the clean up, actually spent.

Hebei Spirit oil spill: $330 million South Korea saw its most expensive oil spill on Dec. 7, 2007, when the Hebei Spirit collided with a crane barge. Roughly 2.8 million gallons of oil spilled into the Yellow Sea, causing oil slicks and precipitating a huge clean up effort. Spills like these, from one-hulled ships, are one of the reasons that single-hull ships are subject to an international ban starting in 2010.

Jiyeh power station: $203 million Oil doesn't have to leak out of a tanker to cause a spill. In July of 2006, Israel bombed an area along the Jieh coast of Lebanon. One of the buildings that sustained damage was the Jiyeh power station, which leaked oil into the Mediterranean Sea as a result of the bombing. Close to 100 miles of coastline were believed to have been affected. Some of the damage was assessed slowly because the Isreali navy instituted a blockade and Lebanese officials had a difficult time surveying what had happened.

Selendang Ayu oil spill: $112 million In December of 2004, the Selendang Ayu freighter ship sank in the Alaskan Aleutian Islands. The Malaysian ship broke in two pieces as a result of the collision and more than 335,000 gallons of oil were released into Skan Bay and Makushin Bay.

Cosco Busan oil spill: $70 million Bunker fuel poured into the San Francisco Bay after the Cosco Busan hit a protective fender of a tower supporting the Oakland Bay Bridge on Nov. 7, 2007. More than 58,000 gallons of fuel leaked into the bay. The ship was renamed afterward the collision to avoid recognition. Its new name is Hanjin Venezia.