In addition to Dheepa’s comments, basically anywhere on the DLR is also a good call for Canary Wharf. It means you can get further out to zones 3/4 if you head East/South, and find cheaper regions. It really depends on your budget and also what you are looking for.
The diagram of the tube map and rental prices is a good indication of areas that will be within your budget and with good connections to Canary Wharf.
From my experience of London, I’d recommend Canada Water/Greenwich - as Dheepa said, it’s just a little less like the city. Personally I don’t really see the attraction of living right in the city (as it’s often dead at the weekend) and the green spaces would be a great addition.
But it really depends what you are looking for. Some people also factor in how easy it will be to get home too, so being East and close to city airport might be a good call: