I've only tried: Xanax (alprazolam), Valium (diazepam) and Ativan (lorazepam) and have found Valium the best overall. But is also probably the closest thing to a body high I've tried.
I heard that temazepam is ridiculously awesome in this aspect, though. Eager to try, will soon.
I used to have a chart bookmarked with each benzo and their dosage conversions along with their effect conversions (anxiolytic, muscle relaxant, sedative). So, I'd think the strongest muscle relaxant would be closest to a "body high" per-se and Valium was the strongest muscle relaxant on that chart. However, I'm not sure if it necessarily means anything to what you're looking for. Also, I do not recall tempazepam being on that list. ...But I reformatted and supidly forgot to save bookmarks, sigh.