vim is good, so too is emacs. But I learnt the hard way why vim has one edge that emacs does not, size (I could be wrong anyone know of an emacs version thats <1Mb). If you know vim at command level you can pick up vi which allows you to edit all but the smallest systems that require tools like
"ed" (installing openBSD
http://goonmail.customer.netspace.net.au/2003OCT230736.html )
If you want to understand more about editors on Unix systems try reading "Raymond E., The Art of Unix Programming, Chapter 13, Complexity, A Tale of Five Editors" ~ http://www.faqs.org/docs/artu/ch13s02.html