There are other methods, however you won't be satisfied with the results.
Wireless signals are affected by many factors including distance, wall density, electrical interference, directional antenna range, etc.
All of these factors will affect your actual wireless range, speed and connection quality.
For serious gaming or video streaming your best bet is a direct Ethernet cable connection. Ethernet is unaffected by wireless interference and will give you a rock solid, stable network connection.
If it is not feasible to run Ethernet cable the next best option would be a set of powerline network adapters http://isp1.us/reviews/netgear-xavb2101-powerline-adapter/
You plug one in by your router and one in the room where you need access and connect them to the devices with standard Ethernet patch cables. The network signals are transmitted over your existing home electrical wiring which will not be affected by wireless interference. There is still overhead in the connection but it is much more stable than WiFi.
Unless you want to run a Ethernet cable to a old router and then configure it as a wireless access point (WAP), then your are going to run into WiFi interference problems.
The old router could be setup to act as a wireless extender. But the setup and performance would be poor when compared to powerline adapters or direct Ethernet connections, especially in the latency stability.
Latency is the delay (ping) in milliseconds that it takes the signal to travel to the server and back. The lower the number the better, but you'll definitely want a ping time of under 120 ms or you'll have major problems with online gaming. Ideally you want less than 80 ms ping to the gaming server.
By nature, interference in wireless systems causes problems with smooth, consistent speeds. Your latency may be 30 ms and wireless interference could cause it to spike to 200 ms or more.
Stick with Ethernet or get a set of powerline adapters.
If you need multiple simultaneous Ethernet connections in your room then you just add an inexpensive 4 or 5 port 100 Mbps unmanaged switch such as these. http://www.amazon.com/s/?_encoding=UTF8&camp=1789&creative=390957&keywords=5%20port%20switch&linkCode=ur2&qid=1373263154&rh=i%3Aaps%2Ck%3A5%20port%20switch%2Cp_72%3A2661618011&rnid=2661617011&tag=excharge-20 You can't get any faster Internet than your ISP provides, so 100 Mbps LAN connections to the router is more than sufficient for most Internet plans.
You connect the Ethernet cable from the router to one of the ports on the switch and can use the rest of the ports to connect your computers, game consoles and other Ethernet devices.
The switch manages the traffic between the devices and the router and the router manages DHCP (IP addressing) and WAN (Internet) traffic.
That being said,
If you must use a wireless connection, you can get a wireless extender or convert an old router as one. http://lifehacker.com/5563196/turn-your-old-router-into-a-range+boosting-wi+fi-repeater
The wireless range extender receives weak wireless signals and repeats them to extend the signal range to greater distances. Some models include Ethernet port(s) in addition to the wireless radio.
Here are the two most popular highly rated models on Amazon.
Securifi Almond - http://www.amazon.com/gp/product/B0087NZ31S/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B0087NZ31S&linkCode=as2&tag=excharge-20
Netgear Universal WN3000RP - http://www.amazon.com/gp/product/B004YAYM06/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B004YAYM06&linkCode=as2&tag=excharge-20
No matter what you decide to buy, as far as the brand goes, the brand is not as important as the model. Some manufacturers release a good model but the next is crap. I would look at the Amazon reviews of models that interest you. Even if you don't buy from Amazon the reviews will tell you a lot about which models to avoid. Look for at least 15 or more reviews with a 4 star or better rating. Read a few and see if they sound like the particular model will work for your application.
Good Luck...