The great thing about Savannah is that it's funded by the FSF, so in contrast to SourceForge, so they care more about the Free Software projects and less about monetizing them. In particular, there are no ads, the whole hosting system is based on Free Software and the website is fast (not overloaded).
Other independent hosters are Gna (http://gna.org/) by the FSF France, as well as BerliOS (http://www.berlios.de/) which has been bootstrapped partly by German public funds.
Wikipedia provides a really good overview:
http://en.wikipedia.org/wiki/Comparison_of_open_source_softw...