Peanuts Releases In The Future:

This is the order of the books in The Complete Peanuts series (at least if the rumors pan out):

1. 1950-52. CHARLIE BROWN
2. 1953-54. LUCY
3. 1955-56. PIG-PEN
4. 1957-58. SNOOPY
5. 1959-60. PATTY
6. 1961-62. SCHROEDER
   
7. 1963-64. LINUS
8. 1965-66. CHARLIE BROWN
9. 1967-68. VIOLET
10. 1969-70. SNOOPY (FLYING ACE)
11. 1971-72. SALLY
12. 1973-74. WOODSTOCK
13. 1975-76. PEPPERMINT PATTY
14. 1977-78. CHARLIE BROWN
15. 1979-80. FRIEDA
16. 1981-82. SPIKE
17. 1983-84. LINUS
18. 1985-86. FRANKLIN
19. 1987-88. LUCY
20. 1989-90. CHARLIE BROWN
21. 1991-92. MARCIE
22. 1993-94. SNOOPY (PERHAPS LAWYER)
23. 1995-96. RERUN
24. 1997-98. PEPPERMINT PATTY
25. 1999-2000. CHARLIE BROWN.

So CB gets 5 covers, snoopy gets 3, Lucy, Linus, Pepperment Patty get 2 and 16 other characters get one cover.

In a way, their pictures show them when they're big parts of the strip. While other characters came and went, these characters (and the way they're listed) is a good way of measuring where the strip was and how it went.

And if I live to 2016 (not necessarily a likelihood, considering how things are going) I'm sure I'll have a whole set.