Egreetings.com
Tons of animated options are sortable by category; then you can add text, upload a photo, and send. Plus, it's easy to group recipients.
Price: Free, but there are ads on the site

Smilebox.com
Choose from hundreds of designs and three music selections, drag and drop pictures or video clips, and add text. Send -- or post to your blog or Facebook page.
Price: Free, with an ad adjacent to the card; $2 per card for no ads and more music selections; $6 per month for unlimited ad-free cards

Scrapblog.com
Sign up to create elaborate, shareable holiday scrapbooks from your photos and videos.
Price: Free