Here is the best order, especially for pseudo classes. A L V VH H A (I pronounce it Al'va ha')
a { color: white; text-decoration: none; } /* bookmark */
a:link { color: red; } /* regular link */
a:visited { color: green; text-decoration: strikethrough; } /* visited link */
a:visited:hover { color: blue; text-decoration: underline overline; } /* visted hover link */
a:hover { color: yellow; text-decoration: underline overline; } /* hover link */
a:active { color: orange; text-decoration: underline overline; } /* active link */
This keeps both visited states and both hover states together as well as staying with the specified order. It also allows for styling of bookmarks such as
<a name="bookmark_name">Bookmark Text</a>
which you can target with
<a href="bookmark_name">Link Text</a>
I find this is great for linking right to a section of a site but where you don't want the bookmark to have an automatic hover style, which it will since it's an anchor tag.
You might prefer VLHA ordering as well, which makes no difference. However CSS spec specified LVHA ordering and, in fact, this one is easy to memorize: i LoVeHA!
Link Visited Hover Active
To quote from the CSS specification:
a:link { color: red } /* unvisited links */ a:visited { color: blue } /* visited links */ a:hover { color: yellow } /* user hovers */ a:active { color: lime } /* active links */
Note that the A:hover must be placed after the A:link and A:visited rules, since otherwise the cascading rules will hide the 'color' property of the A:hover rule. Similarly, because A:active is placed after A:hover, the active color (lime) will apply when the user both activates and hovers over the A element.