Character appearances

Totals

 * Johnny Galecki - Leonard Hofstadter (181 episodes)
 * Jim Parsons - Sheldon Cooper (181 episodes)
 * Simon Helberg - Howard Wolowitz (181 episodes)
 * Kunal Nayyar - Rajesh Koothrappali (181 episodes)
 * Kaley Cuoco-Sweeting - Penny (179 episodes)
 * Melissa Rauch - Bernadette Rostenkowski-Wolowitz (111 episodes)
 * Mayim Bialik - Amy Farrah Fowler (105 episodes)
 * Kevin Sussman - Stuart Bloom (35 episodes)
 * Sara Gilbert - Leslie Winkle (8 episodes)

Series

 * Leonard
 * Sheldon
 * Howard
 * Rajesh

Season 1

 * Leonard
 * Sheldon
 * Penny
 * Howard
 * Rajesh

Season 2

 * Leonard
 * Sheldon
 * Penny
 * Howard
 * Rajesh

Season 3

 * Leonard
 * Sheldon
 * Penny
 * Howard
 * Rajesh

Season 4

 * Leonard
 * Sheldon
 * Howard
 * Rajesh

Season 5

 * Leonard
 * Sheldon
 * Penny
 * Howard
 * Rajesh

Season 6

 * Leonard
 * Sheldon
 * Penny
 * Howard
 * Rajesh
 * Bernadette
 * Amy

Season 7

 * Leonard
 * Sheldon
 * Penny
 * Howard
 * Rajesh
 * Bernadette
 * Amy

Season 8

 * Leonard
 * Sheldon
 * Penny
 * Howard
 * Rajesh
 * Bernadette
 * Amy

All seasons

 * Leonard
 * Sheldon
 * Penny
 * Howard
 * Rajesh
 * Mrs. Debbie Wolowitz