Can you recommend a good low flow showerhead?

The following are two manufacturers that use a maximum of 2.5 gallons per minute (as a comparison, most showerheads before the 1990s used 5-7 gallons a minute) and offer great design at a price:

Hansgrohe (2.5 gallons per minute flow rate)

Kohler (2.5 gallons per minute flow rate)

Alternatively, these two companies offer affordable showerheads with great water efficiency:

Bricor (1 gallon per minute flow rate)

Oxygenics (1.5 gallons per minute flow rate)

Hope this helps!