Bitmapped character appearance in TOS (total appearances). Voice over/stock footage included. Actors in other roles not included.

Data mined from Memory Alpha (http://www.memory-alpha.org).

Kirk 0x800 (78)
Spock 0x400 (79)
McCoy 0x200 (75)
Scott 0x100 (65)
Sulu 0x080 (52)
Uhura 0x040 (69)
Chekov 0x020 (36)
Chapel 0x010 (25)
Rand 0x008 (8)
Leslie 0x004 (55)
Kyle 0x002 (10)
Hadley 0x001 (55)

Note both Hadley and Leslie appear more than Sulu.

The Cage 400
Where No Man Has Gone Before D84
The Corbomite Maneuver FCC
Mudd's Women FC4
The Enemy Within FCC
The Man Trap FCD
The Naked Time FDD
Charlie X ECD
Balance Of Terror FCC
What Are Little Girls Made Of? C54
Dagger Of The Mind E44
Miri E0C
The Conscience Of The King E4C
The Galileo Seven FC5
Court-Martial E41
The Menagerie, Parts I F44
The Menagerie, Parts II C00
Shore Leave EC5
The Squire Of Gothos EC5
Arena FC5
The Alternative Factor E45
Tomorrow Is Yesterday FC7
The Return Of The Archons FC4
A Taste Of Armageddon F45
Space Seed F57
This Side Of Paradise EC4
The Devil In The Dark F05
Errand Of Mercy CC4
The City On The Edge Of Forever FC4
Operation-Annihilate! FD5
Catspaw FE7
Metamorphosis FC5
Friday's Child FE5
Who Mourns For Adonais? FE7
Amok Time EF5
The Doomsday Machine F87
Wolf In The Fold F87
The Changeling FD5
The Apple F27
Mirror, Mirror FE7
The Deadly Years FF4
I, Mudd FE0
The Trouble With Tribbles F65
Bread And Circuses F65
Journey To Babel E71
A Private Little War F75
The Gamesters Of Triskelion F65
Obsession F75
The Immunity Syndrome F77
A Piece Of The Action F65
By Any Other Name F75
Return To Tomorrow FD5
Patterns Of Force F61
The Ultimate Computer FE5
The Omega Glory EC5
Assignment: Earth FE0
Spectre Of The Gun F65
Elaan Of Troyius FF5
The Paradise Syndrome FF1
The Enterprise Incident FF4
And The Children Shall Lead FF5
Spock's Brain FF5
Is There In Truth No Beauty? FE5
The Empath FC1
The Tholian Web FF1
For The World Is Hollow And I Have Touched The Sky FF0
Day Of The Dove FE0
Plato's Stepchildren F51
Wink Of An Eye FF1
That Which Survives FC1
Let That Be Your Last Battlefield FF1
Whom Gods Destroy FC1
The Mark of Gideon FE0
The Lights Of Zetar FF3
The Cloud Minders F41
The Way To Eden FB1
Requiem For Methuselah F41
The Savage Curtain FE1
All Our Yesterdays F00
Turnabout Intruder FB0

It might be interesting to expand this bitmap for staff.