I loved this episode!!! It was yet another brilliant episode of S4, showing us that the writers are truely on top form. And they have my undying love for giving us some hilarious dalogue!!! Like when Prentiss and the new media liason chick where in the club with Viper:

'Jodan: I wouldn't even put you on my Facebook.
Prentiss: You're on Facebook?
Jordan: Yeah, you should friend me...
Prentiss: I will, yeah.....'

Haha!!! Gotta love Prentiss *snuggles*

And, when Garcia and Hotch are discussing Viper and his creepy class:

'Garcia: I abhor the whole 'girls like jerks' thing.
Hotch: Well Garcia, you're one of the good ones.
Garcia: Aw, and so are you sir!'

*snuggles* He really is one of the good ones!!!! *drool*

(Couldn't find exact quotes so that's the best of the top of my head! :P)
Oh, and how could I forget? REID GOT A GIRLFRIEND!!!!!!!!!!!!!! Best. Ending. Ever! :)