While I used empathy for a few years, I much prefer gajim. Partly it's the geek cred that comes with using something a bit less common, but mostly it's because it 1) supports gpg, 2) is highly configurable and 3) is easy to use. It's available in the debian repos. I like mcabber over centerim for the same reason - gpg support. Now, if I only had friends who were as paranoid as I...
[gajim]
Jabber ID: youruser@gmail.com
Resource: Gajim
Priority: adjust to status
Hostname: talk.google.com
Port: 5223
If you use gpg, go to the Personal information tab
You don't need to select 'Use gpg agent' (gpg agent segfaults on one of my boxes)
[mcabber]
The following goes into ~/.mcabber/mcabberrc
set color_background=default #allows transparent background
# Account
set jid = youruser@gmail.com
set password = areallylongandcomplicatedpasswordwhichyoullneverremember
set server = talk.google.com
set port = 5222
set ignore_self_presence = 1 #show self in list?
# GPG/PGP
set pgp = 1
set pgp_private_key = "01100110C1C1C1C1" # get the Key ID from seahorse
set pgp_passphrase_retries = 3
set nickname = blofeld
set spell_enable = 1
set spell_lang = en_GB
set spell_encoding = UTF-8
set cmdhistory_lines = 250
set roster_display_filter = ofdna
set max_history_blocks = 8
set message_autoaway = Auto-away (idle)
set escdelay = 50
alias me = say /me
alias online = status online
alias away = status away
alias dnd = status dnd
alias notavail = status notavail
bind 17 = roster unread_next
bind 24 = roster alternate
bind 269 = roster toggle_offline
bind 276 = roster toggle
bind 521 = buffer up
bind 514 = buffer down
