A long time ago, in a world far, far away, King Odin 'all-father'(Anthony Hopkins) tells his two sons, Thor & Loki(who are possibly twins), about the war against the frost giants over earth, in which the giant's main power source, the casket, was taken away from them.
Plus he tells them that one day one of them will be king, and he will bear the duty of guarding this casket. Zip forward about 12+ years, and Thor (Chris Hemsworth) is about to take the vow of kingship, then party as only as an Asgardian can.
Let's just say that the term 'party-crasher' came from three frost giants who broke into the treasury, killed two guards, yet were promptly defeated by the Destroyer guard. Thor & Odin argue over the next course of action, while Loki (Tom Hiddleston) stands by. Alone later, Thor commandeers Loki, his friend Sif (Jaime Alexander), & the warriors three (Fandral: Joshua Dallas, Hogun: Tadanobu Asano, Volstagg: Ray Stevenson.)Into going to the frost giant's domain to reprimand them and gain information. Needless to say, it does not go over well, and Odin shows up to drag them out of the midst of a near massacre.
As punishment for being such a disrespectful, arrogant brat, Odin takes away Thor's hammer and sends him down to earth. No sooner does he touch down on the New Mexican soil, then he is hit by a van. Talk about a rough first day! As he lays there, groaning in the dirt, the van's occupants, Jane Foster (Natalie Portman), Dr. Eric Selvig (Stellan Skarsgård) and Jane's intern Darcey Lewis (Kat Dennings) run up and ask if he's alright. In response to his loud ranting, Darcey tasers him into unconsciousness.
They check him into a hospital, which later needs some of it's paramedics hospitalized and has a patient missing. Gone in search of his hammer.

This has to be one of my favorite Marvel films, beside Captain America. The great actors, mixed with the plot that will make you laugh, cry, and roar in savage battle-tones makes a memorable teen-adult film.

The bad stuff: There are a few swear words, including the thing that beavers build. There is a suggestion that Thor is given a shot in a private area. Thor is hit by a car (twice), sucked into a vortex, plummets to the ground, receives kicks & punches (which he readily repays), and is attacked by the Destroyer, who, BTW, nearly destructs everything in it's path, including the warriors 3. Selvig gets drunk after taking Thor to a bar. Loki blasts some frost giants with electric charges that leave them with smoking holes in their chests.
A bridge blows up. Loki and Thor battle. A monster chases Loki, Fandral is wounded through the chest by icicles (though not fatally). Odin uses magic to keep Thor's hammer super-glued to a rock. In the earlier battle, villagers are frozen and soldiers are wounded & killed. We get a look at Odin's blood soaked eye socket.
(P.S. Do NOT look on Youtube at the deleted scene of Sif.)

The good stuff: Although Thor & Jane do kiss, it's rather brief, and the at night, they are sleeping in SEPERATE lawn chairs, feet apart. Odin loves his sons, even though technically Loki is not his son. Thor offers Loki forgiveness at the end, to the extent of holding him up when the bridge collapses (after Loki tries to kill him). Selvig wants to protect Jane. Thor and Odin make up, Odin still loving Thor, Thor being more respectful, humble and compassionate. The warriors 3 & Sif love, pester and look out for each other like siblings. The battles are not horribly graphic.

It is close to ranking next to LOTR in my favorite list.