For me, I have yet to find one complete tool that is more portable than C/C++ and a mish mash of open-source libraries.
- glut (or SDL)
- libpng (or SDL_image)
- OpenAL (or SDL_mixer)
- glm (or linmath)
This compiles and runs great on the following platforms
- HTML5 and/or WebGL via Emscripten
- Android (via NDK)
- Blackberry (via Blackberry SDL)
- iOS (via Objective-C++)
- PS3 Homebrew / AltOS
It has the possibility to run on a few others (with a few gotchas and not personally tested)
- NaCL (if libraries are sufficiently wrapped)
- Haiku (in software)
- Windows Store (via Emscripten and WebGL)
- Plan9 (I did test this one ;) Software only for now)
I believe some of the professional AAA console SDKs and homebrew SDKs support many of these libraries but the consumer ones like Xbox Live, PSN etc. are probably a no hope.
If you prefer a single library than the mishmash suggested above (and do not need to support Plan9), then Marmalade provides a similar approach to how it handles cross platform requirements but wraps up all the libraries in a single homogeneous API (and uses proprietary ones rather than things like SDL).