Strange Observations
Hat Positions
Henry-Rolled up with a wide brim and above his ears

Hawkeye-He wears it two different ways. Either rolled up slightly above his ears or slightly rolled up over the top of his ears.

Col. Potter-Rolled up with a wide brim and above his ears. He has his glasses attached to it.
Trapper-Rolled up with a wide brim and cockeyed slightly to the right, covering the top of his right ear.

Charles-Rolled up slightly behind his ears, covering most of the little hair he has.

Frank-Rolled up with a wide brim bhind his ears, covering most of his hair.

BJ-Rolled up slightly, but pushed up his head a lot so it sat basically on the top of his head.
Miscellaneous
-All the the characters write big
-When they change, they turn away from the camera towards the tent wall so anybody outside of the tent could see them changing because there were just screens
-BJ wore most of Trapper's left over Hawaiian shirts. Hawkeye appeared in them occasionally too.
-BJ's straw hat was originally worn by Trapper
-Alan Alda gained weight near the beginning of season nine and if you notice he has to change his wardrobe (this is when he wears some of Trapper's old stuff)
-Doctors always wore their masks tied above their ears and on their necks and nurses always wore their masks tied crossed over on the top of their head
-They were always drinking before surgery (wouldn't they always be drunk and have hangovers during surgery?)
-Even with time differences they made calls at all times of the day
-Jeeps and latrines are destroyed a lot in the show
-Radar and Klinger sometimes hated blood and guts, but they were corpsmen so they should've been used to it
-Even though Korea's temperatures are really extreme they mostly just wore the same outifts
-BJ never follows his own advice
-Sometimes people could speak Korean and sometimes people couldn't
-The theme song music changed as seasons went by
-The orphanage's name changed quite often
-In "Dr. Pierce and Mr. Hyde" in the background as General Clayton is being towed away you can see a guy cheering
-Drafted doctors in the Korean War stay for sixteen months and then they have an option of coming home or having their time extended for two months.  This means that Hawkeye and BJ would've gone home a lot earlier than they did
-It snows a lot in Korea, yet in the show it only snowed a few times
-Father Mulcahy's name changed in the show (Fr. John Patrick Mulcahy, Fr. John Francis Patrick Mulcahy, Fr. John Patrick Francis Mulcahy, can't they make up their mind?)
-Doesn't it seem like in "Dear Dad" that when Hawkeye was being lowered down in the Santa suit that the enemy would have shot him?
-In "Dear Dad", Hawkeye refers to Father Mulcahy as "Red", this is the only time besides the pilot that his nickname "Dago Red" was used.
-Potter's age changed a lot.  He told various stories that could have made him anywhere from 55 to 75.  The amount of years he was married changed a lot too.
-In "Captains Outrageous," everyone salutes Father Mulcahy when he is promoted except for Margaret.  She, being raised in the military should have saluted, but just raised he glass.
-In "Requiem for a Lightweight," Hawkeye spreads the ether (which was water at the time, but he didn't know that) on Trapper's glove and warns him to keep it away from his face.  Hawkeye then uses the same hand he just covered in ether to put Trapper's mouthguard in.
-In "Crisis", in the very beginning when they're all in Henry's office listening to Radar list off the supplies they won't get you can look over at Wayne Rogers and you can see him holding back laughter
-In many episodes you see the edge of a wall that you aren't supposed to see when they move through rooms. I'll show you a diagram:
Sleeping Patterns
Okay, so maybe we are a little too observant, but each one of the characters has their own way of waking up. Here we describe our observations.
Hawkeye-usually wakes up and threatens to kill whoever woke him.  Also sometimes tells about his dreams with some girl.
Trapper-usually jumps when he wakes up, sometimes tells about dreams.
Henry-doesn't always completely wake up right away.  Always seems to have on eye shades.
BJ-I think that BJ loved sleep more than anyone else.  He always wanted to go right back to sleep whenever he got up.
Potter-didn't wake up fully at first, especially when he had a sleeping pill ("No Sweat" showed this well!)
Margaret-the only times you saw her wake, she jumped a little and if it was a man started talking about how rude they were.
Frank-sometimes, Frank seemed to sleep very lightly and woke up whenever someone left the tent.  Other times he slept very heavily, so heavily that Hawkeye and Trapper could take blood from him ("Germ Warfare").  Frank usually woke up ready to go to work.
Charles-snored sometimes, had a red velvet pillow, probably would have had music on while he slept if his bunkmates would have let him.
Radar-talked in his sleep, woke up a little grouchy, since he was usually answering a phone or making a call. He always sleeps with his teddy bear.
Klinger-in earlier episodes, you didn't really see him wake up, but when he was clerk, he usually woke up grouchy, because he was answering the phone
Mulcahy-I don't think you saw much of Father Mulcahy sleeping, though I think he was thrown out of somewhere for snoring too loud.
As the camera moves from one room to the other you see the end of the wall. You aren't supposed to see that.
-Trapper always looks at Hawkeye when he's talking
-In "Iron Guts Kelly," there is a bell beside the bar.  This is not seen in other episodes.
-General Kelly wore his stars on his hat in the O.R.
-In "Bombed," Henry walked into O.R. without a mask, and walked over and talked to the other doctors and nurses, who were operating.
-In "Aid Station," when Klinger, Hawkeye and Margaret are singing the Army song (The Cassions Go Rolling Along) Margaret doesn't sing some of the words, she sings "da da da, da da da, etc. (she doesn't actually say etcetera)." You would think she would sing the whole thing as loud as possible, being from an Army family.
-In "War of Nerves," they group had a large bonfire.  This would never be allowed in a war zone.
This list will continue to grow