Dragonkeeper - Carole Wilkinson (sequel is even better which is great for
 sustained story line)
 Once - Morris Gleitzman
Skellig - David Almond (easy but thoughtful - good for your average year
 6))
 Alex Rider series - Anthony Horowitz
 Helicopter Man - challenging on lots of levels
 His dark materials trilogy - Philip Pulman

 Ned Kelly's Helmet by Paul Stafford ( an Australian author too) has been
 the most amazing HIT with Yr 6 I have ever seen, (especially with boys,
 though both sexes loved it equally) All 4 classes at my school ate it up
 last year and it hasnt been on the shelf since, the kids want to read it
 again & again themselves.

  It is a mix between comedy and adventure/action and historical fiction.
  PLOT
  A classroom teacher sets a task for her students to become bushrangers
 and has set it up with some local businesses that become involved with
 mock robberies. The students have to catch each other with water pistols
 etc. Meanwhile one character has to do duties at an old ladies house and
 ends up swapping places with a real life bushranger through time travel.
 He ends up back in Ned Kelly's time and becomes involved in the Kelly's
 last stand, whilst the mad bushranger plays havoc in the modern town. It
 even has a twist at the end for all you historical buffs that lend itself
 to exploring the novel further and looking at real aspects of the Kelly's
 last stand.
  It is hilarious

Steven Herrick's verse novels for younger readers

 http://www.allenandunwin.com/Authors/apherrick.asp - Do-wrong Ron,  Naked bunyip dancing.

 
 http://www.penguin.com.au/authors/author-author-profile.cfm?AuthorId=0000002169 -
 The spangled drongo, Tom Jones saves the world, maybe Love, ghosts and nosehair.

Half the battle by South Australian teacher/author, Don
 Henderson about a group of kids in year 8, one just moved
 from the country, starting up a football team. Trials and
 tribulations abound, it is funny, moving and realistic.
 
 Danny Allen was here by South Australian author, Phil
 Cummings is based on Phil's childhood in a small country
 town in SA. Funny, family based, about a group of kids doing
 kids' things.  published by PanMacmillan
 
 Pagan series by Catherine Jinks is till being read, and
 leads kids onto the recent release, Pagan's daughter
 
 Another brilliant historical/fantasy writer is Tamora Pierce
 and her latest, Terrier, although long is a wonderful read
 about survival.
 
 The amazing story of Adolphus Tipps by Michael Morpurgo is
 an engrossing novel about WW2 on the English coast, where
 the Americans practised for DDay. True! They cleared out a
 village and the inhabitants had to live elsewhere, while they
 bombed etc. A cat keeps going back to his house and the
 young girl has to crawl through 'enemy' fire to retrieve it.
 An amazing story
 
the My Story books. Cyclone Tracey,
 Refugee, The bombing of Darwin all spring to mind.
 

The Hobbit (because they have probably all seen LoTR)
Captain Mack (James Roy) and its sequel Billy Mack's War
Becoming Billy Dare (Kristy Murray)
Boy Overboard (Gleitzman)
Nips XI and its sequel Nips go National (Starke)
Eagle Strike (Anthony Horowitz)
The Lost Diamonds of Killiecrankie (Gary Crew and Peter Gouldthorpe)
Storm Boy (Colin Thiele)
The Rabbits (John Marsden)
The Tiger Project - Susanna van Essen
I Am Jack / Super Jack - Suzanne Gervay
Dream catcher - Jen McVeity

For Year six Boys

Hatchett - Gary Paulson
 Artmeis Fowl - Eoin Colfer
 Any of Anthony Horowitz books,
 The day my bum went pshycho - Andy Griffiths
 The Wind singer by  William Nicholson
 Northern Lights - Phillip Pullman and any of his other work
 Terry Pratchett - Diggers, Truckers etc
 Boy Overboard - Morris Gleitzman
 Wolf, Calling a dead  man - Gillian Cross
 A Bridge to wisemans cove - James Moloney
 Redwall - Brian Jaques
 The giver- Lois Lowry
 The other side of dark - Joan Lowry Nixon