So as I continue to look at this list I created, I wanted to see how each album fared - what albums had the highest-ranking songs, which albums had the least - that kind of thing. So - here are the albums and their songs as they ranked, in chronological order:
Boy (Average song ranking: 94.8)
33. I Will Follow 
49. The Electric Co. 
88. An Cat Dubh / Into The Heart 
93. Out Of Control 
98. Stories For Boys 
104. Shadows And Tall Trees 
105. A Day Without Me
111. Twilight 
117. Another Time, Another Place 
150. The Ocean
It makes sense that U2's first album would be so relatively poorly represented, with its highest-ranking song "only" at #33. But on the flip side, issuing your #33rd-best song right out of the gate is not too shabby.
October (Average song ranking: 107.6)
69. Gloria 
70. Scarlet 
73. October 
87. Fire
89. I Threw A Brick Through A Window 
120. Tomorrow 
125. Stranger In A Strange Land 
127. Rejoice 
132. I Fall Down 
140. Is That All? 
152. With A Shout
October is widely considered U2's weakest outing. That sentiment is not contradicted here. 
War (Average song ranking: 90.9)
6. Sunday Bloody Sunday 
25. New Year's Day
55. Surrender 
62. 40
96. Like A Song... 
110. Drowning Man 
116. Seconds 
128. Red Light 
155. Two Hearts Beat As One 
156. The Refugee
War, on the other hand, is widely considered U2's breakout album, and with a #6 and #25 ranking in there it shows nicely, if not as well as I may have guessed when starting out. It also points out the limits of this exercise of looking at albums - while War holds up very well as a cohesive album, some if its songs sound very dated today, to me at least. These rankings are meant to look at the songs apart from the albums they come from, so when you smash them back together like I am doing here, it's not an entirely fair view. 
Unforgettable Fire (Average song ranking: 82.4)
8. Pride (In The Name Of Love) 
10. Bad
40. The Unforgettable Fire 
81. A Sort Of Homecoming 
83. Promenade 
90. Wire 
95. MLK 
99. Indian Summer Sky 
158. 4th Of July
160. Elvis Presley and America
Such an odd album. Two top ten songs, and two in the bottom three.  That is some goofy range going on. It also points up the value and risk in experimenting. "Bad" is an experiment that wildly succeeded. "Elvis Presley and America" is one that did not. 
Joshua Tree (Average song ranking: 43.0)
1. Where The Streets Have No Name 
19. I Still Haven't Found What I'm Looking For 
28. Bullet the Blue Sky
29. With or Without You
30. Red Hill Mining Town
36. Running To Stand Still 
37. One Tree Hill 
43. Exit 
57. In God's Country 
80. Mothers Of The Disappeared 
113. I Trip Through Your Wires
The Joshua Tree is still my favorite U2 album. But what this exercise forces me to admit is that a good portion of that is nostalgia. As remarkable an album as it is, I have to really look at whether I place it too high given that it was the album I fell in love with the band on. Still, it is the only album with eight songs in the top fifty. That counts for something. 
Rattle & Hum (Average song ranking: 80.8)
13. All I Want Is You 
47. Love Rescue Me 
66. Desire 
67. Angel of Harlem 
76. Van Diemen's Land 
79. When Love Comes To Town 
91. Silver And Gold 
107. Hawkmoon 269 
123. God Part II 
139. Heartland
A solid enough showing for an odd melange of an album. And of course there are several covers and live cuts here that do not get ranked. 
Achtung Baby (Average song ranking: 40.6)
4. One
5. Acrobat
9. Love Is Blindness 
22. The Fly 
32. Until The End Of The World 
35. Mysterious Ways 
39. Zoo Station 
41. Who's Gonna Ride Your Wild Horses 
51. Ultraviolet (Light My Way) 
65. Even Better Than The Real Thing 
78. So Cruel 
106. Tryin' to Throw Your Arms Around The World
And we tie the record, with Tehran eight songs in the top fifty. Also - three songs in the top ten, and only one out of the top 100 (and barely at that)? This is likely my real favorite U2 album.
Zooropa (Average song ranking: 94.1)
20. Stay (Faraway, So Close!) 
52. The Wanderer 
54. Zooropa
60. The First Time 
109. Lemon
121. Babyface 
122. Daddy's Gonna Pay For Your Crashed Car 
124. Some Days Are Better Than Others 
130. Dirty Day 
149. Numb
This is another example of an album that works much better as an album than if you examine the songs apart from the whole. 
Pop (Average song ranking: 81.8)
2. Please 
23. Gone
24. Wake Up Dead Man
61. Mofo 
74. Do You Feel Loved 
80.5 Dsicotheque
85. Staring At The Sun 
94. If God Will Send His Angels 
112. Last Night On Earth
131. If You Wear That Velvet Dress 
141. Miami 
154. The Playboy Mansion
I really thought I liked Pop more than the numbers suggest I do. 
All That You Can't Leave Behind (Average song ranking: 48.1)
3. Walk On 
7. Beautiful Day 
16. Kite
21. When I Look At The World 
31. Stuck in a Moment You Can't Get Out Of
38. Grace 
48. In A Little While 
64. Elevation 
82. New York 
100. Peace On Earth 
119. Wild Honey
U2's "comeback" album shows very strongly - four songs in the top twenty-five.
How To Dismantle an Atomic Bomb (Average song ranking: 64.5)
14. City of Blinding Lights
42. Vertigo 
44. Yahweh 
45. Original Of The Species 
46. All Because Of You 
53. Sometimes You Can't Make It On Your Own 
59. Love And Peace Or Else 
63. One Step Closer
97. Miracle Drug 
118. Crumbs From Your Table 
129. A Man And A Woman
This is an album that has fallen some in my estimation since its release. 
No Line on the Horizon (Average song ranking: 49.9)
12. Moment of Surrender
18. Breathe
26. No Line on the Horizon
27. Unknown Caller
34. Magnificent
50. I'll Go Crazy if I Don't Go Crazy Tonight
56. White as Snow
68. Get On Your Boots 
72. Cedars of Lebanon
84. Stand-Up Comedy
102. FEZ-Being Born
A pretty strong showing for one of my favorite U2 albums, with six top-fifty songs.  
And after all this analysis, how would I rate the U2 albums? Pretty close to those averages, but with Zooropa and HTDAAB big outliers.
1. Achtung Baby (40.6)
2. The Joshua Tree (43.0)
3. No Line on the Horizon (49.9)
4. All That You Can't Leave Behind (48.1)
5. Pop (81.8)
6. Zooropa (94.1)
7. How To Dismantle an Atomic Bomb (64.5)
8. Rattle & Hum (80.8)
9. The Unforgettable Fire (82.4)
10. War (90.9)
11. Boy (94.8)
12. October (107.6)
Until Whenever