First, I use the Mozilla (Netscape) suite because I can and there is not a better cross-platform substitute. I have all my bookmarks, email, and preferences since 1996 in Netscape/Mozilla format. They reside on a shared FAT32 partition thats accessible under OS2/BSD/Windows/Linux. The Mozilla suite is now called SeaMonkey under 7.10 xUbuntu and IceApe on my beta install xUbuntu laptop.
Under Ubuntu with Seamonkey, you can install the mplayer plugins from Synaptic but you still won't have sound/video. You need to copy the mplayer plugins in