Yes i know i'm kind of a nerd for keeping track, but here is a list of everyone i beat online in mariokart, some of them multiple times. (note: i took peoples names after i beat them at only one race, so they might have won overall, also disconnectors i took their names too, but honestly not too many of them) I have had so much fun playing these people online...they were really the most fun i've had in a long time! I would not count any of these opponents for granted as they were all really hard to beat.
1. el nino
2. nitz
3. silent
4. jam (gg)
5. David. R.
6. Shy king
7. Grumpy mu
8. Psycho
9. Brandon
10 Tayson
11. Jimbo+1
12. James 3
13. Spud
14. dav
15. juan
16. hiya hunny
17. Dark ninja
18. Dfx 3000
19. Polak 007
20. Shorty
21. Slaver
22. Ryan
23. Ash Mini
24. Joelseph
25. Steelers
26. Homerowed
27. Jesus freak
28. Mr. Krank
29. Sir Muter
30. Pc
31. Pk machine
32. Lucky
33. Ron jeremy
34. Enau
35. Toast
36. Mandy
37. Devon
38. Playtime
39. Neo Koto
40. Uto
41. Askicker
42. Chris
43. Tig925
44. Niko Lite
45. iktk
46. joseph
47. ashad
48. bigfoot269
49. Dr. Mario
50. Netty
51. Yoshi 90
52. Dominique
53. Sj
54. Qwerty
55. Maswindu
56. Libsters
57. merp
58. kaleki
59. riot
60. rafael
61. jujo
62. flail
63. Drugas
64. Up yours
65. Labr
66. Wolfman
67. mike

There's always room for more... and on a side note all of these have been exciting matches.