Guys who you feel are going deliberately over time and you have to hustle them out, I'm sure its been mentioned before but happened to me recently.
Lucky I keep an eye on the time, he was trying to make the session last till the last min, I had to sweetly hurry him up coming 10 minutes before the end, then hustle him into a shower, then 'talk, talk, talk at me!' I literally had to pull him up off the sofa to get him to go otherwise he'd have been here all day! As it was he went 15 minutes over time.