What is an episode that blew you away? Meaning, it had you sitting on the edge of your seat and you couldn't wait to see what happens.

Mine would be "Mortal Mission" from season 5. Eeveryone in Walnut Grove contracts Anthrax from tainted mutton. Dr. Baker runs out of medicine so Charles and Jonathan (?) had to travel to another town to get some more. The train carrying the medicine is late. After getting the medicine, Charles and Jonathan are wagon-jacked by some crazed maniac with a gun. The guy steals the medicine, so Charles and Jonathan follow him home and gets the medicine back (barely). That episode is amazing!

Days of Sunshine, Days of Shadow from Season 8. Here's the All Movie Guide synopsis:

In this special 90-minute episode, the first in a two-part story, the Wilders are beset by one calamity after another: A hailstorm destroys their crops, and Almanzo (Dean Butler) suffers a stroke that leaves him semi-paralyzed. Amidst all this strife, Laura (Melissa Gilbert) gives birth to her first child. Assessing the situation, Almanzo's sister, Eliza Jane (Lucy Lee Flippin), invites the young couple to move in with her -- but this hardly brings an end to their troubles.

In the conclusion of a two-part story, the troubles that have recently beset the Wilders continue unabated. Their crops have already been wiped out by hail, and Almanzo (Dean Butler) has been partially paralyzed in an accident. Now, a tornado destroys the couple's home, injuring Laura (Melissa Gilbert), who has recently given birth. In the depths of depression, Almanzo is ready to give up -- but is suddenly galvanized into a valiant effort to get back on his feet, both figuratively and literally, with the help of Laura's father, Charles (Michael Landon).

Both Melissa Gilbert and Dean Butler had very meaty material in this episode, and rose to the occasion. Dean Butler has gone on record as saying this was his favorite episode. :D

For me, it has to be the episode (can't recall which season, but I know it was a later one), where James is shot and falls into a coma. Charles takes him to the woods when everyone thinks he is crazy. When Charles makes the cross, it is just so emotional. Then at the end, when Charles and James come around from behind the monument, that was so powerful.