1. htop
http://htop.sourceforge.net/
sudo apt-get install htop
2. dstat
http://dag.wieers.com/home-made/dstat/
sudo apt-get install dstat
3. bmon
http://freshmeat.net/projects/bmon/
sudo apt-get install bmon
4. iftop
http://www.ex-parrot.com/pdw/iftop/
sudo apt-get install iftop
5. ifstat
http://gael.roualland.free.fr/ifstat/
sudo apt-get install ifstat