Thus far I was really keen on season two's "Revelations" in which Reid got kidnapped. I loved the way they did the flashbacks so that we could learn more about Reid's past, that and I just love episodes about Reid. I have a feeling that season four's "The Instincts" will be my new favourite after what I've seen and heard from the pictures and ads, it just sounds like it's going to be really exciting.

My favorites are Derailed, Lessons Learned, Seven Seconds, and Minimal Loss.

I love Derailed because it has my favorite line "Yeah I'm talking about a magic trick." Then Reid goes on the train and is all adorable. Also, they have a map of the DC subway system on the wall, instead of a Texas system, lol.

Prentiss is badass and awesome in Lessons Learned and Seven Seconds, so that's why I like those two.

And Minimal Loss was an overall fantastic episode. Reid was adorable, Prentiss was amazing, Morgan was badass, Hotch was angry at people who put his team in danger, and Rossi kept calm and collected.

As suspected, I was enthralled with the latest season 4 episode The Instincts, it was brilliant. I'm so frustrated because now we have to wait a week to find out what happens to Reid and his dreams! But this was definitely the best one yet. I just wish Gideon could've been there. :(

There were many good episodes!

I would say those are my favourites: Lessons Learned, Seven Seconds, Mayhem, Minimal Loss, 52 pickup, Demonology and Omnivore.
More to come I think :).

I've got a lot of those. :)

Season 1: L.D.S.K.; Natural Born Killer; Blood Hungry; The Tribe; A Real Rain; Machismo
Season 2: North Mammon; Lessons Learned; Sex, Birth, Death; Distress; Ashes and Dust; Legacy
Season 3: In Birth and Death; Seven Seconds; Lucky; Penelope; True Night; Birthright; Damaged; The Crossing; Tabula Rasa
Season 4: 52 Pickup; Brothers in Arms; Normal; Zoe's Reprise; Pleasure is My Business; Omnivore

I love love love the newest episode conflicted with Jackson Rathbone if anyone missed it they should watch it on you tube it's amazing

riding the lightning
the big wheel

Here's my top 5:
100
Omnivore
Pleasure is My Business
Psychodrama
Ashes & Dust

Revelations
Amplification

My all time favorites are the top two.

plus:
LDSK
Derailed
Fisher King(1,2)
The Big Game
The Instincts
Memoriam
Minimal Loss
LO-FI
Mayhem

99% of my choices are the Reid centered ones obviously. ; )
I had a hard time picking one from this present season yet. Perhaps that is because Matthew was really not around for much of the season due to his injury, or if he was he was not doing all that much. Which kind of sucked.
Until recent episodes that is.

my favs are :
extreme agrressor
memoriam
the big game
pleasure is my business
omnivore
the boogeyman
revelations
a shade of grey
compulsion
l.d.s.k.
the popular kids
what fresh hell
riding the lightning
somebodys watching
p911
the perfect storm
sex,birth,death
no way out
jones
doubt
in name and blood
children of the dark
seven seconds
about face
lucky
penelope
true night
elephant's memory
in heat
tabula rasa
the angel maker
paradise
the instincts
masterpiece
52 pickup
soul mates
demonology
house on fire
amplifcation

as u can see i have ALOT of favs but cm is the only tv show i watch really....(plus reid is hot) hey any1 that sees this will u plz check out mi 100 reasons to watch criminal minds the goal is 100 reasons .... i need ur help its in the forum section XD

The Big Game/Revelations
Amplification
Somebody's Watching
Jones