Here is a list by the Guardian Unlimited of the best movies of 2005, I watched three movies, Sideways, A History of Violence and Downfall. I really loved Downfall a lot, one of the best World War related movie I have ever seen but I found both Sideways and A History of Violence very subpar.

January: Sideways
February: The Woodsman
March: 5 X 2
April: Downfall
May: The Consequences Of Love
June: Kung Fu Hustle
July: Dig!
August: The Last Mitterrand
September: Innocence
October: A History of Violence
November: The Beat That My Heart Skipped
December: Lower City

[source Guardian Unlimited]