Which Wireless Channel Should I Use?

I have an airport express base station and there's lots of other networks around. I occasionally lose signal and I think it's interference from other networks and my base station is only giving about 50% signal, even when I'm in the other room.

I used iStumbler and found out that there's 4 networks on N:

-One on channel 11

-One on channel 7

-Mine on 2

-and another airport on 1

There's also networks on G:

-2 on channel 11

-2 on channel 6

-1 on channel 3

-1 on channel 2

-3 on channel 1

(PS Our home phones are 6 ghz and we live in a fully detached house)