Lorazepam
"Most subtle of the benzos i have tried.  Made me sleepy the first hour or two, but then stabilized anxiety and mood for about 6 hours.  Much longer lasting than it is given credit for.  Good PRN medication.  Other benzos cause some moodiness or depression even.  Although I think Lorazepam can, it is much smoother than others.  It again is too sedating for many people though.  I liked it about as good as Clonazepam, it is better than Valium IMO."