Web site compatibility

I don't do a lot of web site development now but I was under the impression that in recent years, people's experience with different web browsers (IE, Firefox, etc.) was pretty consistent.  Then I started to use Opera (2010) and noticed its problems with Google Docs spreadsheets.  Then we tried to use the PS3 browser to surf the Internet on our HDTV (when we finally purchased an HDTV in 2011) and realized what an abysmal web browser that is. 

When I started using an iPod Touch (4th generation), I was surprised at how well its Safari browser displayed most web pages.  Besides a very intelligent mobile Safari implementation, it appears it was because of the dominance of its cousin, the iPhone, that caused web sites to bend over backwards to accommodate it.  For example, Google Docs presents a very usable interface for spreadsheet editing to the iPod Touch. 

I finally started an ongoing list of how well certain "unpopular" browsers render web sites that I use.  In summary:

• Windows Phone 7 has problems with more "complex" web sites that don't have a mobile version.  But I am sometimes surprised that it is able to handle image oriented web sites such as those found on Tumblr.
• Blackberry Playbook renders most web site excellently, probably because of its Flash support; surfing the net with the Playbook is much like using your desktop computer although there are gaps. 
• I don't have time to fill in the PS3 column but in general, it sucks.  Don't let the included web browser be a selling feature to you.  I have not researched how other game console web browsers such as on Xbox compare