Started by Fred Hembeck (see February 10th), continued by Alan David Doane, and in response to the gauntlet thrown by Mike Sterling, I give you my list.
I started to do 100 (yes, there's some duplication. Hey, more than one person can like it, right), then started a list of things I'd say "d'oh!" over not forgetting and got 100+ there. One other thing: some particular creative runs are noted, and some with just the character. For instance, Spidey at #4 is noted, with particular creative runs mentioned on down the list. Also, any Grimjack by John Ostrander is good
So here it is (in no particular order) 100 Great Things About Comics:
1) Watchmen
2) Peter David
3) EC Comics
4) Spider-Man
5) Little Lulu
6) Adam Hughes Good Girl Art
7) Frank Miller
8) Superman: The Movie
9) Justice League and Unlimited cartoons
10) American Splendor by Harvey Pekar
11) Stan Lee
12) Knights of the Dinner Table
13) Firestorm by Gerry Conway, Al Milgrom and Pat Broderick
14) Camelot 3000
15) The Spirit, especially "10 Minutes" by Will Eisner
16) Don Rosa
17) Grimjack by John Ostrander
18) Lee and Kirby's Fantastic Four
19) Wasteland by John Ostrander and Del Close
20) Empire by Waid and Kitson
21) Marvelman, both Moore and Gaiman's run
22) Giant Sized X-Men 1, 94-143
23) Engelhart and Rogers' Batman
24) Archie Comics Digests
25) Comic Book Reader
26) Liberty Meadows
27) Moore, Bissette and Totleben's Swamp Thing
28) Comic Book Conventions
29) Concrete by Paul Chadwick
30) Marvel Legends Action Figures
31) Terry and the Pirates by Milton Caniff
32) Batman 1989 movie
33) Bitchy Bitch by Roberta Gregory
34) Evan Dorkin
35) Maus I +II
36) Fleischer Superman Cartoons
37) Sugar and Spike by Sheldon Mayer
38) Frank Miller's big Spider-Man Stories (annuals and Marvel Team Up 100)
39) Lynda Carter's Wonder Woman (World War II/ABC series)
40) Kyle Baker
41) Howard the Duck by Steve Gerber
42) Beau Smith
43) Calvin and Hobbes
44) Origins/Sons of Origins of Marvel Comics
45) Peanuts
46) JLA/Avengers
47) Fred Hembeck
48) Love and Rockets
49) Optic Nerve by Adrian Tomine
50) Ernie Colon's Richie Rich
51) Comics blogs
52) Heroes World Comic Book Catalogs of the 70's
53) Super Hero Slurpee Cups
54) Far Side
55) Kenner Super Powers Action Figures
56) Alan Moore
57) Free Comic Book Day
58) Christmas Comics
59) Tony Isabella
60) Comic Book Resources
61) Frank Miller's Daredevil (w/Janson and Mazzuchelli)
62) Alan Moore and Dave Gibbons' "For the Man Who Has Everything" Superman Annual
63) "Superhero Confidential" from Dynamite magazine in the 1970's
64) Previews catalog
65) Amazing Heroes magazine
66) The Original Captain Marvel
67) Innocent Bystander by Gary Sassaman
68) Gen 13/Danger Girl by J Scott Campbell
69) Image Comics
70) X-Men Legends video game
71) Comic Book Legal Defense Fund
72) 100 Page/80 Page Comics
73) Batman The Animated Series
74) Spider-Man & Spider-Man 2 movies
75) ACTOR
76) Marv Wolfman and George Perez' New Teen Titans
77) New Comics Day
78) Akira by Otomo
79) Convention sketches
80) Ambush Bug by DeMattheis and Giffen
81) Green Lantern episode of Duck Dodgers
82) Silver Bullet Comic Books
83) The Norm
84) Comics Buyer's Guide
85) Dork Tower
86) The Original Superfriends Theme w/Ted Knight Narration
87) 'Mazing Man by Rozakis and DeStefano
88) Defenders of Justice CD from Sci Fi Channel
89) Mike Baron and Steve Rude's Nexus
90) Astro City by Kurt Busiek
91) J. Michael Stracynski's "Amazing Spider-Man"
92) Captain America Shield replica, Limited to 2525 copies
93) PvP
94) Alex Ross
95) Neil Gaiman
96) Barry Wein Boy Genius by Judd Winick
97) Lee and Ditko's Spider-Man
98) Super Manga Blast
99) Comics Journal
100) Hogan's Alley

Have enough for at least another list, kids. Stay Tuned!
I'd like to elaborate more on some of the obscure ones at some point. I do take requests for more info.