The best HR is the ones you dont notice. In a way, its a bit like IT support, if their doing their job really well, you should rarely even notice their even there.
The problem is, those HR management types, who feel the need to get noticed so they can get promoted.
We had a really good HR deparment at the last place i worked at. Occasionally, forms appeared on your desk when you asked for them, If you wanted to know about company benefits, you could just walk in and ask them, but on the whole, they stayed out of the way and let people do their jobs and made sure your pay went in on time and correct, did all the paperwork the government requires and so on.
Of course, the place i'm working at now is totally different. Especially at the moment.