To create these characters yourself, hold "alt" down and type the numbers in on the right side of the keyboard (num pad) then let go of the buttons and the character will appear. This is a great way to experiment with new symbols, signs and characters, and it's also good if a button or letter on your keyboard stops working, because you can still type it using the num pad. Just look down the list to find your letter.

You may also be interested in a much smaller, but more rare list of special ascii characters for text art.

Some of the symbols have been listed in bold to separate  them clearly from their descriptions.

Credits to Original Author

1. ☺ White Smiley
2. ☻ Black Smiley
3. ♥ Black heart
4. ♦ Diamond
5. ♣ Clove (Clover/Puppyfeet)
6. ♠ Spade
7. • Black dot
8. ◘ Black square with circle cutout
9. ○ White circle White circle
10. ◙ Black square with black circle
11. ♂ Male Symbo
12. ♀ Female Symbol
13. ♪ Quarter Note
14. ♫ Musical Double Quarter Note
15. ☼ Su
16. ► Play (Forward) or Solid right arrow
17. ◄ Rewind (Backward) or Solid left arrow
18. ↕ Up and down arrows
19. ‼ Double Exclamation Mark
20. ¶ Pilcrow (Paragraph Sign)
21. § The section sign
22. ▬ Long and Thick Minus Sign
23. ↨ Up & down arrows
24. ↑ Up arrow
25. ↓ Down arrow
26. → Right arro
27. ← Left arrow
28. ∟ 90º degree angle
29. ↔ Left and right arrow
30. ▲ Solid up arrow
31. ▼ Solid down arrow
32.  Just a space
33. ! Exclamation mark (bang)
34. " Quote Quote
35. # Pound sign
36. $ Dollar sign
37. % Percentage sign
38. & "And" sign
39. ' Apostrophe Apostrophe
40. ( Left parenthesis
41. ) Right parenthesis
42. * Asterix/astrix (Or star)
43. + Plus sign
44. , Comma
45. - Minus Sign
46. . Period
47. / Forward slash
48. 0 0
49. 1 1
50. 2 2
51. 3 3
52. 4 4
53. 5 5
54. 6 6
55. 7 7
56. 8 8
57. 9 9
58. : Colon (colons)
59. ; Semicolon
60. < Left arrow (Big fish) Less than
61. = Equals sign Equals sign
62. > Right arrows (Small fish) Greater than
63. ? Question mark
64. @ At symbol
65. A
66. B
67. C
68. D
69. E
70. F
71. G
72. H
73. I
74. J
75. K
76. L
77. M
78. N
79. O
80. P
81. Q
82. R
83. S
84. T
85. U
86. V
87. W
88. X
89. Y
90. Z
91. [
92. \
93. ]
94. ^
95. _
96. ` A grave accent
97. a
98. b
99. c
100. d
101. e
102. f
103. g
104. h
105. i
106. j
107. k
108. l
109. m
110. n
111. o
112. p
113. q
114. r
115. s
116. t
117. u
118. v
119. w
120. x
121. y
122. z
123. {
124. |
125. }
126. ~
127. ⌂ A house shaped pentagon
128. Ç A "C" with a cedilla
129. ü A u with a umlaut (or diaeresis) over it
130. é Acute accent over e
131. â "a" with a circumflex over it
132. ä An "a" with a umlaut (or diaeresis) over it
133. à An "a" with a grave accent over it
134. å An a with a circle or dot over it
135. ç A "c" with a circumflex
136. ê "e" with a circumflex on it
137. ë An "e" with a umlaut (or diaeresis) over it
138. è An "e" with a grave accent over it
139. ï An "i" with a umlaut (or diaeresis) over it
140. î An i with a circumflex over it
141. ì An "i" with a grave accent
142. Ä An "A" with a umlaut (or diaeresis) over it
143. Å A capitol "A" with a circle or dot over it (Angstrom)
144. É A capitol "E" with an acute accent over it
145. æ The lower case vowel (grapheme) of the a and e squished together
146. Æ Capitol AE combined into one letter
147. ô A "o" with a circumflex over it
148. ö An "o" with a umlaut (or diaeresis) over it
149. ò An "o" with a mark over it called a grave mark
150. û A u with a circumflex over it
151. ù A u with a grave accent over it
152. ÿ A "y" with a umlaut (or diaeresis) over it
153. Ö A "O" with a umlaut (or diaeresis) over it
154. Ü A "U" with a umlaut (or diaeresis) over it
155. ¢ The "cents" or "cent" sign for currency
156. £ The "pound sign" for currency
157. ¥ The "Yen" sign for currency (Japanese/Chinese) Written in Japanese as 円
158. ₧ Pts Points of Pints sign
159. ƒ A curvy or italic F (italicized)
160. á An a with a acute accent
161. í An i with a acute accent
162. ó An o with a acute accent
163. ú A u with an acute accent over it
164. ñ A n with a tilde ~ over it to make the Spanish enye
165. Ñ A capital n with a tilde ~ over it to make the Spanish enye
166. ª The feminine superscript A
167. º The degrees or degree symbol
168. ¿ Upside down question mark used in Spanish
169. ⌐
170. ¬
171. ½ One half symbol
172. ¼ One quarter symbol O
173. ¡ An upside down exclamation mark (looks like an "i" that sits lower than usual)
174. « Double arrow pointing left
175. » Double arrow pointing right
176. ░ Light shaded block
177. ▒ Medium shaded block
178. ▓ Dark shaded block
179. │ Line
180. ┤Shape
181. ╡Special Line
182. ╢ You can make words with these
183. ╖ Or shapes
184. ╕ Or Mazes!
185. ╣
186. ║
187. ╗
188. ╝
189. ╜
190. ╛
191. ┐
192. └
193. ┴
194. ┬
195. ├
196. ─
197. ┼
198. ╞
199. ╟
200. ╚
201. ╔
202. ╩
203. ╦
204. ╠
205. ═
206. ╬
207. ╧
208. ╨
209. ╤
210. ╥
211. ╙
212. ╘
213. ╒
214. ╓
215. ╫
216. ╪
217. ┘
218. ┌
219. █
220. ▄
221. ▌
222. ▐
223. ▀
224. α The Greek letter "Alpha"
225. ß A German letter, Eszett, scharfes S, sharp S
226. Γ
227. π The symbol for the mathmatical Pi in ascii
228. Σ Greek mathmatical symbol for sum
229. σ Symbol for sum Symbol for sum
230. µ Mu
231. τ  Tau
232. Φ Phi a variation of Phi
233. Θ Theta, the 8th letter of Greek alphabet
234. Ω Omega (24th letter of Greek alphabet)
235. δ The symbol for delta
236. ∞ The symbol or character for infinity (Infiniti)
237. φ Phi (21st letter of Greek alphabet)
238. ε A backwards 3 or curved E - German Epsilon
239. ∩ Upside down U
240. ≡ Equal sign with 3 lines
241. ± Plus and minus (Plus or minus) sign, Plus-minus Symbol
242. ≥ Greater than or equal to symbol
243. ≤ Less than or equal to sign
244. ⌠
245. ⌡
246. ÷ Divide or Division Symbol
247. ≈ Curvy or wavy equal sign =
248. ° Degree or degrees code
249. ∙ Medium height period Medium height period
250. · Dot higher than usual
251. √ (A check mark)
252. ⁿ Superscript N
253. ² Squared symbol, superscript 2 via ascii
254. ■ Black box or square
255.    (Yup, just a space via ascii)