Controlled automatic updates

What's an easy way to remotely deploy updates to a large number of
Windows systems that gives me the control to ignore something big and
destructive like SP2 without ignoring other updates that I want?

By easy I mean I don't want to spend forever trying to set up and
deploy clients for WSUS or pay for SMS or spend any unreasonable amount
of time administering either. I'm not a guru system administrator and I
have a *lot* of more pressing matters to deal with, so a solution
that's as simple as possible is what I'm looking for.

Thanks!