gitignore for Drupal 7 install

.gitignore

# Ignore configuration files that may contain sensitive information.
sites/*/*settings*.php

# Ignore paths that contain generated content.
cache/
files/
sites/*/files
sites/*/private

# Ignore default text files
.htaccess
robots.txt
/CHANGELOG.txt
/COPYRIGHT.txt
/INSTALL*.txt
/LICENSE.txt
/MAINTAINERS.txt
/UPGRADE.txt
/README.txt
sites/all/README.txt
sites/all/modules/README.txt
sites/all/themes/README.txt

# Ignore everything but the "sites" folder ( for non core developer )
# web.config
# authorize.php
# cron.php
# index.php
# install.php
# update.php
# xmlrpc.php
# /includes
# /misc
# /modules
# /profiles
# /scripts
# /themes

We should ignore OS & IDE specific files:

OS generated files

.DS_Store*
ehthumbs.db
Icon?
Thumbs.db

IDE Files

*.sublime-project
*.sublime-workspace
*.komodoproject

and why not ignore .htpasswd too !!