The idea is simple: Whittle down the 500+ pokemon that exist now into a roster of about 150 (give or take 10).  
The rules:
you cannot just post the original 150 
You may remove one creature from any evolution tree. Hence, if you want Pikachu, you can remove Pichu or Raichu, but not both. This is done so that you don't have to be trapped into using some of the funky new evolutions of recent games.
You are also allowed to add pokemon to evolution trees, but not subtract them. For example, Heracross should evolve into Pincer, the way Scyther evolves into Scizor.        
Put starters at the beginning and legendaries at the end

1. Cyndaquil
2. Quilava
3. Typhlosion
4. Totodile
5. Croconaw
6. Feraligatr  
7. Chikorita
8. Bayleef
9. Meganium
10. Charmander 
11. Charmeleon 
12. Charizard 
13. Squirtle 
14. Wartortle 
15. Blastoise 
16. Sentret
17. Furret    
18. Weedle 
19. Kakuna
20. Beedrill
21. Nincada
22. Ninjask
23. Shedinja    
24. Pidgey
25. Pidgeotto
26. Pidgeot
27. Pikachu
28. Raichu
29. Sandshrew
30. Sandslash
31. Vulpix
32. Ninteales
33. Zubat
34. Golbat
35. Crobat
36. Growlithe
37. Arcanine
38. Poliwag
39. Poliwhirl
40. Poliwrath
41. Abra
42. Kadabra
43. Alakazam
44. Farfetch'd
45. Ghastly
46. Haunter
47. Gengar
48. Onix
49. Steelix
50. Krabby
51. Kingler
52. Cubone
53. Marowak
54. Horsea
55. Seadra
56. Kingdra
57. Scyther
58. Scizor
59. Heracross
60. Pinser
61. Tauros
62. Gyrados
63. Lapras
64. Ditto
65. Eevee
66. Vaporeon
67. Jolteon
68. Flareon
69. Espeon
70. Umbreon
71. Leafeon
72. Glaceon
73. Snorlax
74. Dratini
75. Dragonair
76. Sentret
77. Furret
78. spinarak
79. Ariados
80. Natu
81. Xatu
82. Mareep
83. Flaaffy
84. Ampharos
85. Marill
86. Azumarill
87. Yanma
88. Yanmega
89. Murkrow
90. Misdreavus
91. Mismagius
92. Wobbuffet
93. Girafarig
94. Gligar
95. Gliscor
96. Sneasel
97. Weavile
98. Teddiursa
99. Ursaring
100. Skamory
101. Houndour
102. Houndoom
103. Stantler
104. Smeargle
105. Larvitar
106. Pupitar
107. Tyranitar
108. Ralts
109. Kirlia
110. Gardevoir
111. Gallade
112. Makuhita
113. Hariyama
114. Sableye
115. Mawile
116. Aron
117. Lairon
118. Aggron
119. Swablu
120. Altaria
121. Zangoose
122. Feebas
123. Milotic
124. Kecleon
125. Shuppet
126. Banette
127. Tropius
128. Absol
129. Beldum
130. Metang
131. Metagross
132. Shinx
133. Luxio
134. Luxray
135. Combee
136. Vespiquen
137. Riolu
138. Lucario
139. Kabuto
140. Kabutops
141. Shieldon
142. Bastiodon
143. Aerodactyl
144. Raikou
145. Entei
146. Suicune
147. Mew
148. Mewtwo
149. Darkrai
150. Cresselia
151. Lugia
152. Rayquaza
153. Celebi

So I herd you liek mudkipz?

" So I herd you liek mudkipz? "

Too much work, so:
 
The original 150, minus Mewtwo, and replace him with Mew.

" @Damien said:

" So I herd you liek mudkipz? "

Mudkipz and I are cool, but I don't necessairily liek it. Who told you that! "

Squirtle x150 
 
I don't care if he actually wins.  I just wanna hear him saying "Squirtle!  SQUIRTLE!".  It's so fucking cute!

1. Bulbasaur
2. Ivysaur
3. Venusaur
4. Charmander
5. Charmeleon
6. Charizard
7. Squirtle
8. Wartortle
9. Blastoise
10. Cyndaquil
11. Quilava
12. Typholsion
    
13. Treecko
14. Grovyle
15. Sceptile
16. Torchic
17. Combusken
18. Blaziken
19. Piplup
20. Prinplup
21. Empoleon
    
22. Pidgey
23. Pidgeotto
24. Pidgeot
25. Pikachu
26. Raichu
27. Sandshrew
28. Sandslash
29. Nidorino
30. Nidoking
31. Jigglypuff
32. Oddish
33. Vileplume
34. Diglett
35. Dugtrio
36. Abra
37. Kadabra
38. Alakazam
39. Bellsprout
40. Weepinbell
41. Victreebell
42. Poliwag
43. Poliwhirl
44. Poliwrath
45. Politoed
    
46. Geodude
47. Golem
48. Ponyta
49. Rapidash
50. Farfetch'd
51. Seel
    
52. Dewgong
53. Cloyster
54. Haunter
55. Gengar
56. Onix
57. Hypno
58. Exeggute
59. Exeggutor
60. Cubone
61. Marowak
62. Rhyhorn
63. Rhydon
64. Rhyperior
    
65. Staryu
66. Starmie
67. Scyther
68. Magmar
69. Magmortar
    
70. Gyarados
71. Lapras
72. Ditto
73. Eevee
74. Jolteon
75. Vaporeon
76. Omastar
77. Hitmonlee
78. Hitmontop
    
79. Kabutops
80. Aerodactyl
81. Dratini
    
82. Dragonair
83. Dragonite
84. Togepi
85. Togetic
86. Togekiss
    
87. Espeon
88. Umbreon
89. Leafeon
90. Glaceon
    
91. Sneasel
92. Weavile
    
93. Swinub
94. Piloswine
95. Mamoswine
    
96. Houndour
97. Houndoom
98. Larvitar
99. Pupitar
100. Tyranitar
101. Seedot
102. Nuzleaf
103. Taillow
104. Swellow
105. Ralts
106. Kirlia
107. Gardevoir
108. Gallade
     
109. Shroomish
110. Breloom
111. Aron
112. Larion
113. Aggron
114. Wailmer
115. Wailord
116. Zangoose
117. Feebas
118. Milotic
119. Snorunt
120. Glalie
121. Beldum
122. Metang
123. Metagross
124. Starly
125. Staravia
126. Staraptor
127. Gible
128. Gabite
129. Garchomp
130. Rilou
131. Lucario
132. Magnemite
133. Magneton
134. Magnezone
135. Articuno
136. Moltres
137. Zapdos
138. Mewtwo
139. Mew
140. Lugia
141. Regirock
142. Regice
143. Registeel
144. Regigigas
145. Kyogre
146. Rayquaza
     
147. Dialga
148. Heatran
149. Giratina
150. Darkrai

 "you cannot just post the original 150"

" @AgentJ said:

 "you cannot just post the original 150"

I lost interest at this point. The original 150 are the ultimate 150. "

" @MattyFTM said:

" @AgentJ said:

 "you cannot just post the original 150"

I lost interest at this point. The original 150 are the ultimate 150. "

The man speaks the truth! "

Can't be bothered to make an actual list, but I'd take 90 of the Pokemon from the original 150, and add 60 Pokemon from Gold/Silver. None of the Pokemon beyound this point interest me in anyway, but the Gold/Silver roster was awesome.

1. - Dunspace 
2. - 150. - Irrelevant..

This man speaks the truth!

@MattyFTM said:

" @AgentJ said:

 "you cannot just post the original 150"

I lost interest at this point. The original 150 are the ultimate 150. "

The original 151. End of story.

I would want something instead of FUCKING RATATTAS AND PIDGEYS.
 

" @AgentJ said:

 "you cannot just post the original 150"

I lost interest at this point. The original 150 are the ultimate 150. "

" @MattyFTM said:

" @AgentJ said:

 "you cannot just post the original 150"

I lost interest at this point. The original 150 are the ultimate 150. "

this "

Yeah, the original 150. 
 
 
 
See what I did there.
 
 
No you don't see what I did there, because I did nothing.

Ugh, AgentJ and Dethfish have too much time on their hands...
 
The only Pokemon I know from the top of my head are from the first and second generation (I lost interest in the franchise during the third generation), and I can't be arsed to create a roster out of them...

This thread makes me sad.  I can't believe someone (no less 2 people) wrote out a list of their ultimate pokemon roster... Anyway, Snorlax x 150.

Lol yea making a list would take hella long but from what I have seen of the other two lists I would just like to question the exclusion of Flygon.

1. Koffing
2. Koffing
3. Koffing
4. Koffing
5. Koffing
6. Koffing
7. Koffing
8. Koffing
9. Koffing
10. Koffing
11. Koffing
12. Koffing
13. Koffing
14. Koffing
15. Koffing
16. Koffing
17. Koffing
18. Koffing
19. Koffing
20. Koffing
21. Koffing
22. Koffing
23. Koffing
24. Koffing
25. Koffing
26. Koffing
27. Koffing
28. Koffing
29. Koffing
30. Koffing
31. Koffing
32. Koffing
33. Koffing
34. Koffing
35. Koffing
36. Koffing
37. Koffing
38. Koffing
39. Koffing
40. Koffing
41. Koffing
42. Koffing
43. Koffing
44. Koffing
45. Koffing
46. Koffing
47. Koffing
48. Koffing
49. Koffing
50. Koffing
51. Koffing
52. Koffing
53. Koffing
54. Koffing
55. Koffing
56. Koffing
57. Koffing
58. Koffing
59. Koffing
60. Koffing
61. Koffing
62. Koffing
63. Koffing
64. Koffing
65. Koffing
66. Koffing
67. Koffing
68. Koffing
69. Koffing
70. Koffing
71. Koffing
72. Koffing
73. Koffing
74. Koffing
75. Koffing
76. Koffing
77. Koffing
78. Koffing
79. Koffing
80. Koffing
81. Koffing
82. Koffing
83. Koffing
84. Koffing
85. Koffing
86. Koffing
87. Koffing
88. Koffing
89. Koffing
90. Koffing
91. Koffing
92. Koffing
93. Koffing
94. Koffing
95. Koffing
96. Koffing
97. Koffing
98. Koffing
99. Koffing
100. Koffing
101. Koffing
102. Koffing
103. Koffing
104. Koffing
105. Koffing
106. Koffing
107. Koffing
108. Koffing
109. Koffing
110. Koffing
111. Koffing
112. Koffing
113. Koffing
114. Koffing
115. Koffing
116. Koffing
117. Koffing
118. Koffing
119. Koffing
120. Koffing
121. Koffing
122. Koffing
123. Koffing
124. Koffing
125. Koffing
126. Koffing
127. Koffing
128. Koffing
129. Koffing
130. Koffing
131. Koffing
132. Koffing
133. Koffing
134. Koffing
135. Koffing
136. Koffing
137. Koffing
138. Koffing
139. Koffing
140. Koffing
141. Koffing
142. Koffing
143. Koffing
144. Koffing
145. Koffing
146. Koffing
147. Koffing
148. Koffing
149. Koffing
150. Koffing    

" @AgentJ said:

 "you cannot just post the original 150"

I lost interest at this point. The original 150 are the ultimate 150. "

Something something Probopass.

" i know nothing about any pokemon beyond the original 150... besides, how can you possibly have 150 favorite pokemon? "

" @AgentJ said:

 "you cannot just post the original 150"

I lost interest at this point. The original 150 are the ultimate 150. "

  
1.Snorlax, that Poke so dope he be chilling all day.

Ya know, I really liked the first 251, up through Gold & Silver.

All Mudkipz and Bublasaur.
 
BULBASAUR NUMBA ONE!

" @AgentJ said:

 "you cannot just post the original 150"

I lost interest at this point. The original 150 are the ultimate 150. "

" @AgentJ said:

 "you cannot just post the original 150"

I lost interest at this point. The original 150 are the ultimate 150. "

" Ya know, I really liked the first 251, up through Gold & Silver. "

Everything that was released up until gold and silver. I have no problem with the new ones, I just don't really know what they are all about.

You should link all of these to images, son.
 
But I guess that's too much to ask, even for a list-maniac like you (*challenge has been set*).