I dont want to be the only downsider here but...
I have hosted a few sites on SourceForge (the current count is 2 projects), and I have had a few problems with it.
The CVS repository has caused me and the team a few issues (commiting work, only to see that the cvs tree is not updated for over an hour, leading to waits in the dev time), the CVS tree becoming corrupted and having to be wiped clean a few times (though kudos to the guys behind SourceForge, the handled all my help requests very quickly), and a few minor niggles with the web hosting (pages not getting updated on the main site when I have uploaded them).
On the whole though, SourceForge is a well run, and efficient hosting site, well worth looking into. Another site worth looking at is BerliOS, which is very similar to SourceForge. Its originally a German site, and their translation is sometimes a bit off, but it seems ok. I have recently moved my main project here, but have not had enough time to see the improvments over SourceForge.
Hope you get sorted