This is an addendum to the out-of-date list at
http://www.aspfaq.com/sql2005/show.asp?id=20
Now that SQL Server 2005 is over a year old (what a big boy you are!), the beta builds are irrelevant, but the post-RTM builds fix some issues that may be quite important to you. If you want database mirroring, for example, this feature was not supported until SP1.
What follows is the list of builds since the latest entry at the URL above. If you're familiar with these build numbers, you probably know the drill — run SELECT @@VERSION; and if you don't recognize the build number returned (RTM is 9.00.1399.06; SP1 is 9.00.2047), then it will hopefully be in one of these two lists.