Met and interviewed a number of film, TV and music personalities and, thankfully, never had a negative experience with any of them. Always been great; Zach Galligan in particular is an absolute gent, as is Speed from Soilwork. The guys in My Dying Bride are a top bunch too.
Kane Hodder almost choked me to death, and I've drunkenly made a few celebs a little uncomfortable (in sober hindsight!) but they've never reacted negatively towards me. Dave Parker is great (wish he'd come back to the UK at some point!) -- bummed a couple of smokes off him, and he's a real easy person to speak to. I think having self-deprecation comfortably nailed really is key to that whole personable touch.
Jason Newstead of Metallica was a particularly genuine and funny guy when I met him. James and Lars seemed a little more "off", but nothing offensive.