Unsportsmanlike conduct (also called unsporting behaviour or ungentlemanly conduct) is a foul or offence in many sports that violates the sport’s generally accepted rules of sportsmanship and participant conduct. Examples include verbal abuse or taunting of an opponent, an excessive celebration following a scoring play, or feigning injury. The official rules of many sports include a catch-all provision whereby participants or an entire team may be penalised or otherwise sanctioned for unsportsmanlike conduct.

Sledge early, sledge often

Sledging is a term used in cricket to describe the practice whereby some players seek to gain an advantage by insulting or verbally intimidating the opposing player. The purpose is to try to weaken the opponent’s concentration, thereby causing him to make mistakes or underperform. It can be effective because the batsman stands within hearing range of the bowler and certain close fielders; and vice versa. The insults may be direct or feature in conversations among fielders designed to be overheard.

There is debate in the cricketing world as to whether this constitutes poor sportsmanship or good-humoured banter.^[1] Sledging is often mistaken for abuse, and whilst comments aimed as sledges do sometimes cross the line into personal abuse, this is not usually the case. Sledging is usually simply an often humorous, sometimes insulting attempt at distraction. Former Australian captain Steve Waugh referred to the practice as ‘mental disintegration’.

Family values : Mark Waugh and James Ormond

The Australian cricket legend and one of the best fielders in the slip cordon, Mark Waugh was lip sealed after the lesser known English all-rounder James Ormond replied to Mark’s stupid statement.

When Ormond walked out to the pitch, Mark said to him “F**k me, look who it is. Mate, what are you doing here? There is no way you’re fit to play for England.” Ormond without a speck out doubt replied, “Maybe not, but at least I am the best player in my family.”

Close to home: Glenn McGrath and Eddo Brandes

One of the most famous moments is when Glenn McGrath was bowling to Zimbabwean tailender Eddo Brandes who missed every ball.

McGrath went up to Brandes and said “why are you so fat”, in a split second Brandes replied “because every time I make love to your wife, she gives me a biscuit.”

Tit for tat: Viv Richards & Greg Thomas.
In a county match in England, Thomas was bowling to Richards and getting a few to whizz past the bat. After Richards played and missed another one, Thomas said: “It’s red, it’s round. Now fucken hit it!”.This obviously angered Richards who proceeded to hit the next ball out of the ground. Richards: “You know what it looks like now go and get it.”

Source:
http://topyaps.com/top-10-epic-cricket-sledging-incidents-of-all-time
https://en.wikipedia.org/wiki/ICC_Cricket_Code_of_Conduct
https://en.wikipedia.org/wiki/Sledging_(cricket)
http://top20cricketsledges.blogspot.com.au/