The latest stable released version is 4.3.4 available from http://il.php.net/downloads.php
It's almost certainly the one you want.
There is a 4.3.5 Release Candidate build but you really don't want to use it unless you are doing some testing or know of a particular issue it resolves.
The 4.3.3 stuff is history. I don't know where that version number showed up on the link you provided but it was probably just out of date documentation. Again, the only reason not to use 4.3.4 would be if you knew of some specific issue that required 4.3.3.
Of course, if you are really brave then you could try php 5.0 Beta 3.
