Pert Plus is, arguably, the "guy shampoo".

Most guys don't really know what conditioner is, or why they might need it, and that uncertainty makes them nervous, so they cover their bases by using this "Shampoo plus Conditioner" 2-in-1 miracle product. It smells decent, they clearly mark different versions for "fine or oily hair", "'normal' hair", and "dry or damaged hair", and it generally seems to do a good job of getting hair clean.

One note of caution; I cannot track down where I heard this phrase of warning, but I have always heeded it to the utmost:

"Pert Is Not A Lube"

There is an associated tale of a young man who thought the green stuff would aid in masturbation, and he lived to regret putting a fairly powerful chemical cleaner on his sensitive parts.