Earth: 6
Earthbind Totem
Stoneskin Totem
Stoneclaw Totem
Strength of Earth Totem
Tremor Totem
Earth Elemental Totem
Fire: 6 (*7 with talents)
Fire Elemental Totem
Totem of Wrath*
Flametongue Totem
Frost Resistance Totem
Fire Nova Totem
Searing Totem
Magma Totem
Water: 5 (**6 with talents)
Fire Resistance Totem
Mana Spring Totem
Healing Stream Totem
Mana Tide Totem**
Poison Cleansing Totem
Disease Cleansing Totem
Air: 8
Wrath of Air Totem
Tranquil Air Totem
Windfury Totem
Windwall Totem
Nature Resistance Totem
Sentry Totem
Grace of Air Totem
Grounding Totem
Default 25, potentially 26.
I've found that people generally don't put on their toolbars:
Flametongue Totem
Windwall Totem
Nature Resistance Totem
Frost Resistance Totem
Fire Resistance Totem
Sentry Totem
and sometimes Stoneclaw Totem.
Others, however, make a macro button for the Resistance totems, making one of them left-click, another right-click, another scroll-mouse-button.