Using UTF-8

Putty
Terminal --> Keyboard --> The Function key and keypad --> VT100+

Window --> Appearance --> Font Settings --> Change...
字型 : 細明體
字集 : CHINESE_BIG5

Window --> Translation -->
Received data assumed to be in which character set: UTF8
Check : Treat CJK ambiguous characters as wide

~/.vimrc
set termencoding=utf-8
set encoding=utf-8
set fileencodings=big5,utf-8,gbk,euc-jp,euc-kr,utf-bom,iso8859-1
autocmd BufNewFile,BufRead w3mtmp* set fileencoding=utf-8


~/.bashrc
export LC_ALL=zh_TW.UTF-8
export LANG=zh_TW.UTF-8

Reference:
Putty
http://www.chiark.greenend.org.uk/~sgtatham/putty/