It used to be really common to see notes on websites saying "best viewed in..." or little rotating graphics or something else along the lines of "view this site in my favorite browser, or I can't promise what it will look like." But these days I rarely see that message (or one like it) at all. That's why I was so surprised to see the message on the HTML5 Rough Guides site (my inspiration post this week) stating that you should use Internet Explorer to view it. I ended up ignoring the message and viewing it anyway, and while it didn't work well on my iPad, it seemed to have little trouble with Chrome on my Mac.
It is frustrating being a web designer and having to have such a wide variety of browsers to support, but with the introduction of HTML5 and Internet Explorer 9 and now 10, that support is coming back to a central location. Why would a site want to deliberately limit its viewers by requiring (or suggesting) that they use a different browser than the one they prefer? Especially when they insist on a browser like IE that only works on Windows, so you are deliberately snubbing several popular operating systems (Macintosh, iOS, and Android). I recommend you never tell your readers what browser to use.
Do you tell your readers what browser they should use? Why or why not? Let me know in the comments.