I'm working on developing my opening repertoire and trying to find a d4 opening that's not straight down the obvious path but still relatively straightforward. I've played alot of Scotch in the past and I'm trying to expand a little. I like some elements of the main line QGD but it's so over analyzed I was looking for something just a little to the side.

 Any opinions on the exchange variation?

 

What about the Catalan.

I've read about alot more of the Scotch Game variants than I've played. In fact I've never played any of the Gambits (as I'm not sure I'm good enough to turn the extra initiative into compensation for the pawn or pawns lost). I'm around 1400 and generally play the Kasparov Knight exchange on c6, forcing double pawns on black and a little cramping. I like it as it's a little like the Lopez exchange except you dont' lose the bishop.

 I'll have to look at the Catalan a little more. The Colle system is interesting, and is all over my favorite book (Chernev's Logical Chess Move by Move, yeah I'm an adult beginner) but I'm a little afraid of the locked in bishop at the beginning.

 After reading Logical Chess is when I started looking at d4 and so far have played mostly straight QGD online, haven't played any d4 in a tournament yet.

I tried Seirawan's choices (Pirc, KID, then tried Sicilian Dragon instead of Pirc) as black, but didn't really have much luck. These days, I'm playing pretty straight lines as black in response to whatever I'm presented, just developing and looking for small advantages. I usually end up playing QGD black side or Ruy Lopez main lines alot.

Why dont you try to play caro kann with black, or sveshnikov/lasker/pelikan sicilian if you are agressive player?
With white, there are a lot of choices.
Long time ago, I asked a very good chess trainer what opening should I play. I had first category at that time. The answer: "you could play any opening, as long as you dont have over 2600 elo; any opening in playable"
He is an international master, and a great chess trainer.