According to Official Guinness Records,
With 110,240 officially sanctioned competitions held in Japan between May 2003 and July 2009, Mushiking: King of the Beetles holds the record for the most official tournaments held. Mushiking is a combination of an arcade game and a collectible card game developed by SEGA.
Mushiking is a collectable card arcade game, where players use barcoded cards to conduct battles between in-machine;these cards are given out every time you play.
For a complete list of 2007 records, please visit 2007 Guinness Records in Japan.