On Saturday, February 9th (15:47:53 GMT), the 40 millionth griddler was solved by cerbe. The solved puzzle was Minimalism: Playing the Trumpet (ID: 34795).

Almost made it:
claret who solved the 39,999,999th puzzle and burcusevinc who solved the 40,000,001st puzzle.

The former records are:
The 1 millionth puzzle was solved on January 12th, 2004, by drworm01
The 2 millionth puzzle was solved on June 3rd, 2004, by calle
The 3 millionth puzzle was solved on September 29th, 2004, by khaos
The 4 millionth puzzle was solved on December 16th, 2004, by FlyingDuck
The 5 millionth puzzle was solved on February 23rd, 2005, by myran

The 6 millionth puzzle was solved on April 19th, 2005, by lironpaz
The 7 millionth puzzle was solved on June 12th, 2005, by lmgoodall
The 8 millionth puzzle was solved on August 2nd, 2005, by hickhack
The 9 millionth puzzle was solved on September 18th, 2005, by jmsriv
The 10 millionth puzzle was solved on November 4th, 2005, by BESNAG1

The 11 millionth puzzle was solved on December 15th, 2005, by Tunrida
The 12 millionth puzzle was solved on January 24th, 2006, by martek1987
The 13 millionth puzzle was solved on February 28th, 2006, by delsol
The 14 millionth puzzle was solved on April 1st, 2006, by Lies109
The 15 millionth puzzle was solved on May 5th, 2006, by Melu

The 16 millionth puzzle was solved on June 5th, 2006, by Adar
The 17 millionth puzzle was solved on July 5th, 2006, by anbaevent
The 18 millionth puzzle was solved on August 5th, 2006, by zelvaB
The 19 millionth puzzle was solved on September 5th, 2006, by asaf_r_
The 20 millionth puzzle was solved on October 7th, 2006, by trombonetom

The 21 millionth puzzle was solved on November 6th, 2006, by atandjmc
The 22 millionth puzzle was solved on December 5th, 2006, by titimatt
The 23 millionth puzzle was solved on January 5th, 2007, by cherrypez
The 24 millionth puzzle was solved on February 2nd, 2007, by parsky
The 25 millionth puzzle was solved on March 3rd, 2007, by laxrunners

The 26 millionth puzzle was solved on March 28th, 2007, by martusia136
The 27 millionth puzzle was solved on April 22nd, 2007, by hell28k
The 28 millionth puzzle was solved on May 16th, 2007, by wau
The 29 millionth puzzle was solved on June 7th, 2007, by yoannaa
The 30 millionth puzzle was solved on June 27th, 2007, by mgckmdn

The 31 millionth puzzle was solved on July 22nd, 2007, by ay_cim
The 32 millionth puzzle was solved on August 15th, 2007, by Yemilka
The 33 millionth puzzle was solved on September 7th, 2007, by CrazyBliep
The 34 millionth puzzle was solved on September 30th, 2007, by tonnylaanplat
The 35 millionth puzzle was solved on October 23rd, 2007, by sar-tsa

The 36 millionth puzzle was solved on November 13th, 2007, by affinia
The 37 millionth puzzle was solved on December 5th, 2007, by jankadz
The 38 millionth puzzle was solved on December 30th, 2007, by rogerd66
The 39 millionth puzzle was solved on January 20th, 2008, by Georgia75
The 40 millionth puzzle was solved on February 9th, 2008, by cerbe