You also should consider what other people are using around you as well. All wireless routers use essentially the same wireless spectrum (2.4Ghz and 5.0GHz (well b/g does not use 5.0GHz)). There are essentially 12 channels (0-11, in the US) which you can (legally) set your wireless router to use (for b/g networks), and ideally, you want to be 6 channels away from anyone else that is within range (i.e. 0, 6, 11, are the most commonly used default channels as a result of this recommendation).
If you have a laptop, it can be easy to do a wireless scan and see what other wireless networks are available and what channels they are using. If you can (not always possible), change your channel to one that is not being used which is 6 channels away from the other wireless networks that you detect. At a minimum, use 3 channels of separation if you can not get 6.
This can make a huge improvement on your performance without doing anything else since you are no longer dealing with as much crosstalk from their networks (as your wireless router and devices still see the traffic over their networks as well when you are using the same channels and will need to filter their network data out as well as deal with retransmitting data when you both transmit data at the same time (causing the messages to get merged together).