For browsers ubuntu has firefox, epiphany, konqueror, as well as several others.
I’d rather have Opera 9 instead of Firefox. Trouble is, if you try to uninstall Firefox via apt-get or Synaptics, it will try to uninstall the ENTIRE OS, which would definitely break your system.
BTW, I absolutely hate the newest version of Gaim (2.0). It doesn’t function as nicely as Gaim 1.5.