There were seven different unimetallic commemorative Two Pound coins issued from 1986 to 1996.
From 1997, there one or two different Two Pound coins issued in most years.
See the link below to the Royal Mint.
The modern British Five Pound coin is not issued as a general circulation coin, but as a commemorative. It is legal tender, but is not often accepted by businesses due to its non-familiarity.
The modern Five Pound (Crown) coin was first issued in 1990 and has been issued for the following occasions.
1990 - Queen Mother's 90th Birthday
1993 - Queen's Coronation 40th Anniversary
1996 - Queen's 70th Birthday
1997 - The Queen and Prince Philip's 50th Golden Wedding
1998 - Prince Charles' 50th Birthday
1999 - Diana, Princess of Wales Memorial Crown
1999-2000 - Millennium Crown
2000 - Queen Mother's 100th Birthda
2001 - Death of Queen Victoria 100th anniversary
2002 - The Queen's Golden Jubilee
2002 - Queen Mother Memorial Crown
2003 - The Queen's Coronation 50th Anniversary
2004 - Entente Cordiale between Great Britain and France 100th Anniversary
2005 - 200th anniversary of the Battle of Trafalgar
2005 - 200th anniversary of the death of Horatio Nelson
2006 - The Queen's 80th Birthday
2007 - Diamond Wedding Anniversary of the Queen and the Duke of Edinburgh
2008 - 450th Anniversary of the Accession of Queen Elizabeth I
2008 - Prince Charles' 60th Birthday
2009 - 500th anniversary of the accession of Henry VIII
2010 - 350th Anniversary of the Restoration of the Monarchy
2011 - 90th Birthday of the Duke of Edinburgh
2011 - Royal Wedding
2012 - Diamond Jubilee
The Royal Mint estimates that there were 1,470,000,000 One Pound coins in circulation as at 31-Mar-2008.
British Coins have been minted for over 1,000 years.
The Royal Mint estimates there to be 27,827,000,000 currently in circulation.
The Royal Mint advises that as of the 31st of March, 2009, there were 1,483,000,000 One Pound coins in circulation.
The Royal Mint advises that there were 38,505,000 British 2010 One Pound coins (Royal Shield) minted.
The Royal Mint produced 89.886 million 1996 One Pound coins, many of which are still in circulation.
These coins are still in circulation. Unless they are in mint condition, they are worth One Pound.
Assuming that you refer to British coins, the 1991 5, 10 and 50 Pence coins are no longer in circulation and have little or no value. The 1, 2 and 20 Pence coins and the One Pound coins are still in circulation and are worth those amounts respectively.
If your asking about the British ten pound note, then it is still in circulation and there are no plans to withdraw it. (February 2009)
Coins have been used for thousands of years. The first British coins that are still currently in circulation are the 1 Penny and 2 Pence coins.
Please ask one question at a time in the format - "What is the value of a 1983 British One Pound coin?" These coins are still potentially in circulation so, unless they are part of a Proof or uncirculated mint set or are individual Proof or uncirculated coins and in absolute mint condition, they are worth One Pound.
The One Pound coin replaced the One Pound note in the British currency in 1983. Pound coins include the One Pound and Two Pound coins, and the Five Pound coin which is issued as a commemorative but is still legal tender.
All years of issue of the British One Pound coin are still in circulation, so there would be no need to "change up". The British One Pound coin is legal tender up to any amount, so all banks should be able to accept them.
The British uni-metal Two Pound coins issued from 1986 to 1996 were intended to be a commemorative coin, not a circulating coin, although they are legal tender. If these coins are in their original packaging and still in mint condition, they could get up to £7 GBP. Circulated, they are worth Two Pounds.
General circulation legal tender British coins in circulation in 1984 were - Halfpenny - withdrawn and demonetised in 1984 Penny Two Pence Five Pence Ten Pence Twenty Pence Twenty-Five Pence Fifty Pence One Pound The term "New" referring to Pence, was dropped from 1982 onwards. The gold Half-Sovereigns, Sovereigns, Two Pound and Five Pound coins are not considered general circulation coins, but are non-circulating legal tender.
The coin you describe is a general circulation Gibraltar One Pound coin commemorating the discovery of a Neanderthal skull in 1848. These coins are still in circulation so, unless they are part of a Proof or Uncirculated mint set or are individual Proof or Uncirculated coins and in absolute mint condition, they are worth One Pound (GBP) in Gibraltar.
All British coins minted in 2000 are still in circulation. They are worth whatever is inscribed on them.