Your house does have some great bones, lovely floors, and nice architectural details, but I see what you mean that it has that college feel. I'm totally taking liberties and having fun decorating your room.
I'm "giving" you less than $600 budget to decorate the room, but you could completely change the look and feel of the room for less with a bit more resourcefulness (hello garage sales!), and you certainly wouldn't need to do it all at once.
The following items are from Craigslist. You can often negotiate a lower price, but I'll plan on these amounts to fit into the above budget. I don't know where you are exactly, and am not familiar with Chicago, so some of this may not be convenient to you, but it gives you an idea of what you can do with a small budget.
I used a color scheme of tan and red, since the sofas are tan and the rug (which I think is SO pretty!) is tan and red. A larger rug will anchor the room nicely. Of course, you could pick a different color scheme and make it work just as well. The warmer colors will make it cozier.
$200 - Sofa, chair and ottoman on Craigslist
$40 - Tan and red rug on Craigslist
$50 - TV armoire.
$50 - Desk with hutch to replace the printer table
$35 - End table (paint red to match the rug, instead of green)
$75 - Keep looking for it on Craigslist for a bigger book case. This one from IKEA matches the TV armoire, but is $150. Try to get it used for $75.
If you sew, you could make coordinating curtains, pillows, and a table cloth for very little. If not, you could buy them relatively cheap as well.
Add curtains with texture (four panels, about $60), a cozy blanket ($10). Hang a warm, framed art piece or tapestry over the sofa and over the TV (art is so subjective, but look on Craigslist, overstock.com, etsy.com, make something larger yourself, frame a poster, etc.) Throw a table cloth on the table with a vase of fresh flowers (and move the lamp and computers off the table!) A large mirror would be nice next to the door rather than the bookshelf and small pictures, since it will reflect back the light from the windows. Try stores like Big Lots!, Marshalls, Ross, or Tuesday Morning for this kind of thing.
As for layout:
Swap the sofa to the opposite wall, where the TV is, and put the TV where the sofa is with the chair at an angle next to it. Use the ottoman as a coffee table or additional seating as needed. (We have this set up and it's very convenient.) Otherwise, if you're keeping the futon and not adding a chair, put a tall houseplant next to the TV. Put the TV in an armoire so it isn't the focal point of the room and the electronics are contained. A
Hang a larger piece of art or a tapestry over the sofa. Add an end table with a lamp and a few framed photos next to the sofa, then the bookshelf and narrow, tall desk to contain the clutter.