This is a list of the plugins i use on this or other blogs:

• Akismet
  
  This is the default plugin to stop spam and it is inlcuded by the default with wordpress,you only have to get a API key on wordpress.org and activate it.
• Google XML Sitemaps
  
  Generate XML-Sitemap for you blog, this is supported by Ask.com, Google, MSN Search and YAHOO
• Subscribe To Comments
  
  Allow your readers to follow comments on your blog and get an email when a new comment has been added
• WordPress Database Backup
  
  This plugin allows you to get a backup of you wordpress database on demand, or you can schedule it so you get the backup on your database in your email hourly, daily or weekly
• NextGEN Gallery
  
  If you want to create a photo gallery to your blog, this is a great option, it handles EXIF data, IPTC data, create thumbnails, slideshows, allows you to order photos. create albums, etc.