The problem is that last time I looked at these tools, they all sucked. I migrated code hosting and website for my project to github but left issue tracking on Google Code because the github API doesn't let you do any kind of high fidelity import of issues. I hope GH find a way to do some kind of reasonable issue import soon.

The API doesn't, but if you contact the Github team, they have ways of doing much higher fidelity bug imports if you give them massaged data.

Here is an example of a project we imported from Bugzilla:

https://github.com/translate/pootle/issues?page=47&q=is%3Ais... (all issues below id ~3200 are imported).

Here is the tool I wrote for the occasion:

https://github.com/jleclanche/bugzilla-to-github/