I'm going for a third playthrough, and I've been taking it slow in Greenvale this time on Easy.
The things you can find are nothing short of awesome.
 In the police department, there's a desk that says "thomas" on it with a bunch of frilly patterns everywhere with a.... lingerie magazine on it
Also in the police department everywhere is a picture of a man with a dog... and that man is SWERY!
 Aside from looking at things closely, I'm looking around at who spends time at certain places. For example, Richard really MUST like Anna's mother as York suggested and spends lots of time there.
 
Has anyone else looked around? I really hope to get people to organize amongst themselves what areas to look for cool details.

Well, just from watching Spoony's Let's Play of DP I can say that  

" Well, just from watching Spoony's Let's Play of DP I can say that  

SPOILER WARNING: Click here to reveal hidden content.

the game hints at Forrest Kaysen early on in the game, where York observes a map with "fat man dolls" on it across the country, with an empty plate labeled "Washington state"

"

I haven't had a chance to look at others, but the license plate on George's truck is HESTHE1.

this one might be a little more obvious, but  SPOILER WARNING: Click here to reveal hidden content. 
also, the picture you see of Polly and the townsfolk from 50 years ago is in that same spot the whole game.

" this one might be a little more obvious, but  SPOILER WARNING: Click here to reveal hidden content. 
also, the picture you see of Polly and the townsfolk from 50 years ago is in that same spot the whole game.

there is a red tree at george's house as well as at the sheriff's department. i love how all these hints are dropped in the game that most of us pay no attention to until it's all been revealed

"

Yeah, but realistically how would you get close enough to see it in the game.

This is sort of related, but seeing little stuff like this made me think how cool it would be if there was a game that just dumped you into a town like Greenvale and forced you to solve a crime by observing tiny stuff like this, like who spends time where, maybe break into people's houses.

If you could get me screenshots of Thomas's desk (or a sketch would be great too) I would love you forever.  I really, really want to see it.
I would trade fanart or fic or something for creepy, stalkerish details about everything that has to do with Thomas.   (I really need to get back to writing fic for this.) 

sorry, I'm lending DP to a friend at the moment...

 
Beating the epilogue multiple times will get you different scenes after the credits. Most everyone knows the first time you beat it is: 

The storage room in the police station(the one across the kitchen) has a closet filled with red rain coats in it.
 
Yeah, I sadly knew who the killer was from then on.

My friend and I peeked in on Nick and Olivia arguing ):

 So what is behind the secret door in the Special Room?    

" The storage room in the police station(the one across the kitchen) has a closet filled with red rain coats in it.  Yeah, I sadly knew who the killer was from then on. "

"  So what is behind the secret door in the Special Room?     "

Don't know if this is much of a secret or anything but while wathcing the lets play on Spoony's site the first profiling scene once all the clues are collected shows events of the story.
 
Still want an UK release of this game to just mess around in

" @mutha3 said:

" The storage room in the police station(the one across the kitchen) has a closet filled with red rain coats in it.  Yeah, I sadly knew who the killer was from then on. "

Was this in the other-world police station? "

I think the endings after the main one with Emily and York with the girls and Thomas at the diner are random, 'cause I got

Oh, and some of the store names are spoofs of other games, like Mash Bros Mart.  You really need to look for them to spot them, I guess.
And the music that seems misplaced (Like when you first meet George and Emily, Emily gets the nice Goddess Theme when first introduced while George gets the weird Suspicious music or when you meet Thomas for the first time) foreshadows them.  o 3o//
Also, found out that music that Carol sings at the end of the original Rainy Woods Trailer plays (piano version) in Thomas's house, in the record, when Thomas is dancing his weird dance, but when it plays is random.