Have you figured out yet that I'm obsessed with Mid-Century modern design? Even so, alas, I don't have the income to go the *authentic* route, what with a child and his future at stake (i.e. I'd rather save for his ivy-league education), so I usually go the knock-off or "inspired-by" route. I like Ikea because they are a Swedish company that is fully in tune with traditional Danish-ish aesthetic. What that means is: clear lines, simplicity and an eye for detail.
To put together a mid-century room, you have to think in terms of keeping it clean. Get rid of the knick-knacks that clutter your shelves, tables and mantle. You will feel a weight lifted once you do this. Then look around you and decide what looks over-stuffed, dark and depressing. Then get rid of that, even if it's your sofa (I just did this). Replace with clean, neutral-toned pieces that give more than a wink-and-a-nod to the masters of mid-century modern. And don't forget the shag rug, no smaller than 8x5.
Here's what I found at Ikea that might work in such a room:
The Trollsta tray table - $99
The Vejmon Coffeetable - $199
The Tyosand Sofa in Orange - $699
The Besta Storage Unit in Red - $650
The Patrik Visitor Chair in Charcoal - $149
The Tobias Chair - $99
The Gilbert Chair $49.99
The Fusion Table & Chairs Set - $299
The Karlstad Armchair - $399
The Ramvik Coffeetable $139
The Jamsunda Sideboard - $479
The Mandal Sidetable - $69.99
The Benjamin Stool - $19.99
The Horup Floor Lamp - $16.99
The Regolit Floor Lamp - $39.99
The Knappa Pendant Lamp - $24.99
The Septim Pendant Lamp - $24.99
All of these pieces are clear and distinct winks to mid-century pieces that will make you happy every time you use it. I know mine do - and when you get sick of it, because of the excellent prices, you can decorate your room all over again!