This version also ignores all Magento core files

Magento 1.4+ .gitignore (core excluded)

# put it into magento install dir

app/code/core/
app/code/community/Phoenix/Moneybookers

app/design/adminhtml/default/default/
app/design/frontend/base/default/
app/design/frontend/default/default/
app/design/frontend/default/blank/
app/design/frontend/default/iphone/
app/design/frontend/default/modern/
app/design/install/
app/etc/modules/Mage_All.xml
app/etc/modules/Mage_Api.xml
app/etc/modules/Mage_Bundle.xml
app/etc/modules/Mage_Centinel.xml
app/etc/modules/Mage_Compiler.xml
app/etc/modules/Mage_Downloadable.xml
app/etc/modules/Mage_Weee.xml
app/etc/modules/Mage_Widget.xml
app/etc/modules/Phoenix_Moneybookers.xml
app/etc/config.xml
app/etc/local.xml.additional
app/etc/local.xml.template
app/locale/en_US/
app/locale/de_DE/
app/locale/de_CH/
app/locale/it_IT/
app/locale/fr_FR/
app/Mage.php

cron.php
cron.sh

downloader/
errors/

favicon.ico
includes/

# index.php (should be version controlled for multi-domain stores
index.php.sample
install.php

js/
# js/blank.html  
# js/extjs/
# js/lib/
# js/prototype/
# js/spacer.gif  
# js/varien/
# js/calendar/  
# js/flash/
# js/index.php  
# js/mage/ 
# js/scriptaculous/
# js/tiny_mce/

lib/
# lib/3Dsecure/  
# lib/flex/
# lib/googlecheckout/
# lib/LinLibertineFont/
# lib/PEAR/
# lib/Varien/
# lib/Zend/

LICENSE_AFL.txt
LICENSE.html
LICENSE.txt

media/downloadable/
media/import/
media/catalog/product/cache/

# nbproject/
pear/

php.ini.sample

pkginfo/

shell/
# shell/abstract.php  
# shell/compiler.php  
# shell/indexer.php  
# shell/log.php

skin/adminhtml/default/default/
skin/frontend/base/
#skin/frontend/default/blank/
skin/frontend/default/blue/
skin/frontend/default/default/
skin/frontend/default/french/
skin/frontend/default/german/
skin/frontend/default/iphone/
skin/frontend/default/modern/
skin/install/

var/.htaccess
var/backups/.htaccess
var/backups/*gz
var/cache/
var/export/
var/report/
var/session/
var/tmp/

pear

.htaccess.sample