I didn't see The Hangover so cannot comment.
But Avatar best movie? It's a clear sign of the whole dumbing down of the whole awarRAB business, and one of the reasons I stopped watching these things.
It is no longer about genuine talent and originality, it is about selling movies. They have just become another marketing tool...watch for the new posters with the awarRAB slapped all over them, and probably a re-release of the movie as well.
I will grant you that Avatar deserves accolades for some of it's technical achievements, but in terms of acting, story and directing it really did not stand out in any way at all.
I much preferred District 9 and Moon as better sci-fi fantasy movies, even though they are far from perfect.
But I am astonished at Cameron's best director award - for a movie that consisted largely of actors reacting to blue/green screens, computer graphics and men running about in skintight black leotarRAB with dots stuck all over them.
If this is indicitive of what is considered a 'good director', then I despair.