SONIC UNLEASHED

For this achievement you have to talk to everyone in the game. There are 99 people in total, so go to every place and talk to everyone who has a little orange arrow above their head. What will make things easier is if you buy the bookshelf in Spagonia for 300 rings and go to pickles lab and in the directory section it will tell you how many people you have seen.
Apotos : 10 people
Spagonia : 23 people
Chun-Nan : 9 people
Mazuri : 9 people
Holoska : 6 people
Shamar : 21 people
Adabat : 6 people
Empire city : 9 people
Eggmanland : 4 people
The hot dog vendor people and the item selling people are included in this achievement.
Also you have to speak to the mysterious character Wentos when you see him, he appears everywhere apart from eggmanland.
In spagonia theres a woman called Natalia she wants you to find her daughter lucia, you have to find her and talk to her also for the achievement.
Also you have to talk to Amy aswell. You will find her throughout the middle of the game "thanks to redchaoschao94"

Social Butterfly - 30G (Original Achievement)

Difficulty: 2/10

To get this Achievement, you simply need to speak with every character in the game. Below is a list of every character and where they live. There are 99 people to meet.

Apotos: 10

1. Milos (Old Man)(Shop Owner)
2. Lambros (Old Man)
3. Alexis (Young Boy)
4. Eric (Old Man)
5. Gregorios (Old Man)
6. Lucas (Old Man)
7. Sandra (Old Woman)
8. Anastasia (Old Woman)
9. Ice Cream Vendor (Shop Owner)
10. Hot Dog Vendor (Apotos)(Shop Owner)

Spagonia: 23

11. Gigi (Old Man)
12. Otto (Old Man)
13. Barbara (Old Woman)
14. Irma (Old Woman)
15. Josef (Old Man)(Shop Owner)
16. Marcantonio (Man)
17. Ciccio (Man)
18. Denise (Woman)
19. Aida (Woman)
20. Natalia (Woman)
21. Franco (Man)
22. David (Man)
23. Raimondo (Man)
24. Federica (Woman)
25. Lilli (Woman)
26. Dora (Woman)
27. Elio (Young Boy)
28. Mauro (Young Boy)
29. Lucia (Young Girl, looks like young boy)
30. Ippolita (Young Girl)
31. Prof. Pickle's Asst. (Man)
32. Professor Pickle (Old Man)
33. Hot Dog Vendor (Spagonia)(Shop Owner)

Chun-Nan: 9

34. Zonshen (Old Man)
35. Lin (Old Woman)
36. Shuifon (Old Man)
37. Wang (Man)(Shop Owner)
38. Jinlin (Woman)
39. Hualin (Woman)
40. Chun (Young Boy)
41. Yilin (Young Girl)
42. Hot Dog Vendor (Chun-Nan)(Shop Owner)

Mazuri: 9

43. Gwek (Old Man)
44. Kwami (Man)
45. Essie (Woman)
46. Yawa (Young Boy)
47. Kofi (Man)(Shop Owner)
48. Ana (Woman)
49. Kwod (Young Boy)
50. Yaya (Young Girl)
51. Hot Dog Vendor (Mazuri)(Shop Owner)

Holoska: 6

52. Jari-Pekka (Old Man)
53. Ursule (Old Woman)(Shop Owner)
54. Jari-Thure (Man)
55. Sarlanna (Woman)
56. Marketa (Young Girl)
57. Hot Dog Vendor (Holoska)(Shop Owner)

Shamar: 21

58. Ehsan (Old Man)
59. Hizir (Old Man)
60. Raniya (Old Woman)
61. Iman (Old Woman)
62. Utba (Man)
63. Mufid (Man)
64. Erhan (Man)
65. Labib (Man)
66. Sa'id (Man)
67. Satif (Man)
68. Ara (Woman)(Shop Owner)
69. Dimah (Woman)
70. Musaid (Man)
71. Shadi (Man)
72. Sammar (Woman)
73. Layla (Woman)
74. Safi (Young Boy)
75. Sadiq (Young Boy)
76. Samia (Young Girl)
77. Yasmine (Young Girl)
78. Hot Dog Vendor (Shamar)(Shop Owner)

Adabat: 6

79. Teanchai (Man)
80. Jamal (Man)
81. Kaeo (Man)(Shop Owner)
82. Rudi (Woman)
83. Nagi (Young Girl)
84. Hot Dog Vendor (Adabat)(Shop Owner)

Empire City: 9

85. Louie Montaine (Man?)
86. Boss (Man)
87. Def Big (Man)
88. Elizabeth (Woman)
89. Charles (Man)
90. Robert (Man)(Shop Owner)
91. Li'l Kate (Woman)
92. Brenda (Woman)
93. Hot Dog Vendor (Empire City)(Shop Owner)

Eggmanland: 4

Note: You must beat the game to unlock Eggmanland's Hub and get these 4.

94. EF-DC1998 (Robot)
95. EF-MD1991 (Robot)(Shop Owner)
96. EF-XB2006 (Robot)
97. Hot Dog Vendor (Eggmanland)(Shop Owner)

???: 2

Wentos: (Man with Chao Puppet)(Shop Owner)

Amy: (Pink Hedgehog) Found in Spagonia in the early part of the game, and Shamar in the rest.

Note: Wentos will appear randomly in any city but Eggmanland.

Not so much a solution but a warning

I beat the game and then started going for the achievement. I was not able to locate Brenda (92) which is the newspaper reporter going around asking you questions. According to other guides she appears first in either Chu-Nan (after defeating the Dark Gaia Phoenix) or Mazuri. I couldn't find her in either place. I later found that someone on gamefaqs reported that she likes to vanish out of existence and screw up your save file.

So, if she isn't in Chu-Nan's hub after defeating the boss then delete your save file and start the game over because I learned about this glitch the hard way after beating the game...

Achievement should be marked as buggy -