This is basically where we are at:

Limited Edition Variant Library Chronology

1) Spider-Man #1-10
2) Fantastic Four #1-10
3) X-Men #1-10
4) Avengers #1-10
5) Spider-Man #11-19, Annual #1
6) Fantastic Four #11-20, Annual #1
7) X-Men #11-21
8) Incredible Hulk #1-6
9) Avengers #11-20
10) Spider-Man #20-30, Annual #2
11) Uncanny X-Men #94-100, Giant-Size #1
12) Uncanny X-Men #101-110
13) Fantastic Four #21-30
14) Captain America from ToS #59-81
15) Silver Surfer #1-6
16) Spider-Man #31-40, Annual #2
17) Daredevil #1-11
18) Thor from JiM #83-100
19) Silver Surfer #7-18
20) Iron Man from ToS #39-50
21) Fantastic Four #31-40, Annual #2
22) Spider-Man #41-50, Annual #3
23) Dr. Strange from ST #110-111, 114-141
24) Uncanny X-Men #111-121
25) Fantastic Four #41-50, Annual #3
26) Thor from JiM #101-110
27) Avengers #21-30
28) Fantastic Four #51-60, Annual #4
29) Daredevil #12-21
30) Thor from JiM #111-120, Annual #1
31) X-Men #22-31
32) Sub-Mariner from TtA #70-87
33) Spider-Man #51-61, Annual #4
34) Fantastic Four #61-71, Annual #5
35) X-Men #32-42
36) Golden Age Marvel Comics #1-4
37) Uncanny X-Men #122-131, Annual #3
38) Avengers #31-40
39) Hulk from TtA #59-79
40) Uncanny X-Men #132-140, Annual #4
41) Daredevil #22-32, Annual #1
42) Fantastic Four #72-81, Annual #6*
43) Captain America Comics #1-4*
44) Spider-Man #62-67, Annual #5, Spectacular #1-2
45) Iron Man from ToS #51-65*

*Coming soon or already out depending on when you read this.