Here are the tools I use to live my life on the command line:
Client: Mutt
Filtering: procmail, imapfilter
Search: mairix
General Web
Client: Lynx, Links, Elinks, w3m
Tools: wget, aria2c, curl
Web Services
Toodledoo: toodledo (ruby gem)
Misc search engines: Surfraw
Google Calendar: gagenda
Ebay: esniper
BBC Iplayer: get_iplayer
Google Drive: gdrive
Google Mail: mutt (via IMAP)
StackExchange: sx.el (via Emacs)
Social Media
Twitter: Rainbowstream
Facebook: fbstream (RIP)
Hackernews: hackernews (via Emacs)
Chat: centerim
Software
Editor: Emacs, Vim
Icinga: icli, qicinga
RSS: Newsbeuter, Feednix
Weather: weatherman
File Viewers
MS Word docx: docx2txt.pl
MS Word: antiword
PDF: pdftohtml
RTF: unrtf
(all of these can be integrated into mutt via ~/.mailcap)