Mozilla Firefox @ Mozilla.org
I've been using the release candidate for sometime now and apart from making the buttons a bit bigger than previous versions, it's worked quite well. Final version is now out and available for Win32 in Zip (6mb) & EXE installer (4.7mb) versions. Linux has a simple tar.gz file (7.8mb) or a tar.gz containing an installer (8.1mb).
Mozilla FTP. Some nice themes for Firefox -> MozThemes by Aaron Spuler.:)