Networking gurus: help with wireless repeater/extender

I'm looking for a reliable, inexpensive, easy to setup and install wireless extender or repeater. Here's the background:

I live in house with three roommates. Three of the bedrooms are upstairs, and one is downstairs in the corner of the house. The router is upstairs in my room. It's a D-Link DIR-655, which replaced a Linksys WRTG-54 because it had 3 external antennas and supposedly had a wider range. We're an entirely Mac household, if that makes any difference.

The DIR-655 has been totally fine, but the downstairs bedroom is still having reception issues. The wireless connection is spotty/weak, and she cannot do streaming video. I tested the speed/latency in her room, and versus mine and the others upstairs, it is extremely weak.

So, we've decided to try and strengthen the signal downstairs. What is the best course of action for this? Based on my research, it's with a wireless repeater or extender.

Does anyone have any personal recommendations to that end? I've done many network setups, but never dealt with this before. Any help or insight with product suggestions would be much appreciated. Thanks in advance.

 

Wireless signals travel out horizontally, vertically they are very limited.
Do all you can to move it as far from vertical as possible.

 

Get yourself a pair of these and move your router closer to the central portion of the house.
Amazon.com: Netgear HDXB111 Powerline HD Plus Ethernet Adapter Kit: Electronics

That way you aren't managing multiple link points and you make the best use of a very good router you already have.

 

Usually just moving the router horizontally, such as another place in the room will fix the problem.