This Smashing Magazine article gives some tips on making your websites fun and entertaining.

• “There are many pages common to almost all websites. By taking a typical website page or experience and making it fun and memorable, you can set that website apart by improving on the ordinary.”
• Make a humorous 404 error page.
• Don’t just make your website memorable - “Making Your Message Memorable”.
• “Another way to get a website’s message across is through storytelling — and a fun approach can help ensure that the story you tell is a memorable one.”
• Design for emotion, “including trust, hope, surprise, delight - even love”

http://www.smashingmagazine.com/2012/02/24/a-fun-approach-to-creating-more-successful-websites/