Can anyone give me a summary of what has happened up to this point in Game of Thrones? A friend has been coming over to my house every weekend to watch it with me, and I don't have the time to grind through the seasons.
It begins with Robert Baratheon as king of Westeros. He is married to Cersei Lannister, and has three children: Joffrey, Myrcella and Tommen.
Eddard (Ned) Stark is lord of Winterfell and Warden of the North lands of Westeros. He is married to Catelyn Stark and has five children: Robb, Sansa, Arya, Bran and Rickon, and one illegitimate son: Jon Snow. He is friends with Robert Baratheon. Theon Greyjoy also lives with them as a hostage, as his father Balon Greyjoy revolted in the past. Jon Snow shortly joins the Night's Watch, a band of soldiers who protect Westeros from savages in the north.
Ned looks through the lineage books of house Baratheon and finds that every single Baratheon child has black hair. Joffrey, Myrcella and Tommen all have blonde hair. Guess who else has blonde hair? Cersei Lannister's twin brother, Jaime. Ned realises that Cersei and Jaime have been doing the nasty. Robert Baratheon is killed while hunting and Joffrey takes the throne. Ned challenges this as Joffrey, being that he isn't Robert's heir, has no right to the throne. He orders the city guard to seize Joffrey and Cersei and imprison them. Instead, as the city guard are either loyal or bribed by the Lannister family, they imprison Ned instead. Joffrey orders that Ned be killed for his treason, and Ned is beheaded while his youngest daughter Arya watches.
This causes a whole lot of trouble. Robb, Ned's eldest son, raises an army to avenge his father's murder and to take the iron throne. Stannis Baratheon, Robert's oldest brother, moves to take the throne as he believes he should be next in line. Renly Baratheon, Robert's other brother, also moves to fight for the throne. We end up with four main armies: Lannisters vs Northmen vs Renly vs Stannis.
Stannis has teamed up with a mysterious priest, Melisandre of Asshai. Melisandre summons a spirit, which moves to Renly's camp and stabs him to death. One down.
The Lannisters and the Northmen are stuck in stalemate. Robb seems to be winning but he doesn't push very far. Jaime Lannister is taken captive for a while, but is released by Catelyn Stark, as she believes that Lannisters still hold her daughters and she hopes to make a trade. This doesn't happen.
Stannis Baratheon attempts to attack the Lannister's forces by river. The Lannisters absolutely annihilate him and he retreats back to his island.
In order to cross a river to meet the Lannister forces, Robb was forced to make a bargain with the lord who owns the bridge. He promises to marry one of the lord's daughters. Being that the lord's daughters are hideous wenches, Robb isn't exactly smitten. Instead, he falls in loved with a battlefield medic called Talisa and she becomes pregnant. Instead, Catelyn's brother agrees to marry a daughter.
Meanwhile, King Joffrey has arranged to marry Margaery Tyrell, to unite the two powerful and rich families.
Remember the lord of the bridge crossing? He's insulted that Robb didn't marry his daughter. He plots with the Lannisters and at the wedding between Catelyn's brother and a daughter, his men stab Talisa to death, cut off Robb's head and sew it onto a direwolf's body and kill a large chunk of the Northmen.
Theon Greyjoy betrays the Starks and attacks their home castle. Bran and Rickon escape, and Theon kills two other children to make everyone think they are dead.
Jon Snow has been working his way up the ranks of the Night's Watch. They go to explore the land above the Wall, finding a force of savages led by Mance Rayder preparing to storm the wall and attack the north. Most of the Night's Watch is killed by Wights (think scary ice zombies). Jon escapes and crosses back into the north of Westeros.
While all of this is going on in Westeros, Daenerys Targaryen is living in Essos as the last remaining member of the Targaryen family, from whom Robert Baratheon took the throne. She marries Khal Drogo, the leader of a tribe of horsemen. She receives three dragon eggs as a wedding gift. Khal Drogo dies, and Dany puts the dragon eggs in his funeral pyre. Three dragons hatch and she becomes Mother of Dragons. Dany explores Essos, freeing slaves and gathering a strong following. She plans to sail to Westeros and take the throne when her dragons are strong enough.
That's as up to date as I am; I haven't watched season 4 yet. I have read the books but I wouldn't want to spoil anything that hasn't yet aired. It may not be chronological, but it's very difficult to do that when the story jumps back and forth so much. This is as TL;DW I could give you without it all becoming completely incomprehensible. xD
EDIT: Tyrion Lannister remains awesome throughout it all. You asked for main points and he isn't really at the forefront of battle. He is rather the brains behind the brawn. The Lannisters also arrange for him to marry Sansa Stark, which neither of them are happy with.