| The Riddle (1xCD
, Maxi-Single) | Germany, 1999 |
ZYX Music (ZYX 9133-8), Media Records (ZYX 9133-8) |
| The Riddle (1xCD
, Maxi-Single, Enhanced) | Europe, 2000-05-29 |
ZYX Music (ZYX 9133D-8), Media Records (ZYX 9133D-8) |
| The Riddle (Remix) (1xCD
, Maxi-Single) | Germany, 2000 |
ZYX Music (ZYX 9133R-8) |
| The Riddle (1xCD
, Maxi-Single, Enhanced) | Netherlands, 2000 |
Noise Maker Benelux (NM1020712), Media Records (NM1020712), Noisemaker (NM1020712) |
| The Riddle (1xVinyl
, 12", 45 RPM) | Germany, 2000-01-06 |
B.I.G. (BIG 5045-12), ZYX Music (BIG 5045-12), Media Records (BIG 5045-12) |
| The Riddle (1xCD
, Maxi-Single) | Denmark, 2002 |
Iceberg Records (ICE CDM 147) |
| The Riddle (1xVinyl
, 12", 33 ⅓ RPM, Promo) | US, 2001 |
Arista (ARDP-3963) |
| The Riddle (1xCD
, Single) | France, 2000-03-14 |
EMI Music France (7243 8882392 0), R.K.G. Records (7243 8882392 0), BXR (7243 8882392 0), DLA (7243 8882392 0) |
| The Riddle (1xCD
, Single) | Netherlands, 2002 |
Noise Maker Benelux (NM1020702), Media Records (NM1020702), Noisemaker (NM1020702) |
| The Riddle (1xCD
, Maxi-Single) | Netherlands, 2000 |
Noise Maker Benelux (NM2028402), Media Records (NM2028402), BXR (NM2028402) |
| The Riddle (1xVinyl
, 12") | France, 2000-03-14 |
EMI Music France (7243 8882396 8), R.K.G. Records (07243 888 239 6) |
| The Riddle (1xCD
, Maxi-Single, Enhanced) | UK & Ireland, 2001-02-19 |
RCA (74321 82623 2) |
| The Riddle (1xCD
, Maxi-Single, Promo) | UK & Ireland, 2000 |
Media Records (RID2 - 74321 825252), BXR (RID2 - 74321 825252), BMG (RID2 - 74321 825252), RCA (RID2 - 74321 825252), C2M (RID2 - 74321 825252) |
| The Riddle (1xVinyl
, 12", 45 RPM, Maxi-Single, Promo) | UK & Ireland, 2000 |
BMG (RID 1), RCA (RID 1), BXR (RID 1), Media Records (RID 1) |
| The Riddle (1xCD
, Maxi-Single) | France, 2000 |
DLA (888 324-2), R.K.G. Records (888 324-2), BXR (888 324-2), EMI (888 324-2) |
| The Riddle (1xCD
, Maxi-Single, Reissue) | Germany, 2001-05-21 |
ZYX Music (GDC 2228-8) |
| The Riddle (1xCD
, Maxi-Single, Misprint) | Germany, 1999 |
ZYX Music (ZYX 9133-8), Media Records (ZYX 9133-8) |
| The Riddle (1xVinyl
, 12", Maxi-Single, 45 RPM) | Canada, 2000 |
Popular Records (POP 4066) |
| The Riddle (1xVinyl
, 12", 33 ⅓ RPM, Promo, White Label) | US, 2001-03-05 |
Arista (ARDP-3958) |
| The Riddle (1xCD
, Maxi-Single) | Germany, 2000 |
ZYX Music (ZYX 9133-8), Media Records (ZYX 9133-8) |
| The Riddle (1xCD
, Maxi-Single, Misprint) | Germany, 1999 |
ZYX Music (ZYX 9133-8) |
| The Riddle (1xCD
, Maxi-Single) | Germany, 2000 |
ZYX Music (ZYX 9133-8), Media Records (ZYX 9133-8) |
| The Riddle (1xCD
, Maxi-Single, Misprint) | Germany, 2000-05-02 |
ZYX Music (ZYX 9133-8), Media Records (ZYX 9133-8) |
| The Riddle (1xCD
, Maxi-Single) | Germany, 1999 |
ZYX Music (ZYX 9133-8), Media Records (ZYX 9133-8) |
| The Riddle (J&B Remixes) (1xVinyl
, 12") | France, 2000 |
EMI (7243 8883246 5), R.K.G. Records (7243 8883246 5), DLA (7243 8883246 5), BXR (7243 8883246 5) |
| The Riddle (1xCDr
, Unofficial Release) | Benelux, 2002 |
Noise Maker Benelux (NM 1020702), Media Records (NM 1020702) |
| The Riddle (1xBetacam SP
, Advance, PAL) | UK |
Arista (none) |
| The Riddle (1xCD
, Maxi-Single, Enhanced) | Netherlands, 2000 |
Noise Maker Benelux (NM1020712), Media Records (NM1020712), Noisemaker (NM1020712) |
| The Riddle (1xVinyl
, 12", 33 ⅓ RPM, Limited Edition) | Germany, 2022-02-11 |
ZYX Music (MAXI 1065-12) |
| The Riddle (1xCD
, Maxi-Single, Misprint) | Germany, 2000 |
ZYX Music (ZYX 9133-8), Media Records (ZYX 9133-8) |
| The Riddle (1xCD
, Single) | Netherlands, 2002 |
Noise Maker Benelux (NM1020702), Media Records (NM1020702), Noisemaker (NM1020702) |
| The Riddle (Original Longer Mix) (1xFile
, WAV) | Worldwide, 2022-02-11 |
ZYX Music (DIG160575) |
| The Riddle (1xCD
, Single) | Netherlands, 2002 |
Noise Maker Benelux (NM1020702), Media Records (NM1020702), Noisemaker (NM1020702) |
| The Riddle (5xFile
, AAC, EP) | Worldwide, 2022 |
ZYX Music (none) |
