Winner: 2004 Krark-Clan Incubator (Myr Incubator) Combo
2nd place: 2008 Kithkin
tied for 3rd: 2008 Demigod Red, 2002 Psychatog & 2006 Solar Flare

64 decks single elimination (decks from 1994-2010):

A World Championship winning deck from each year
1994 World Championship deck (before Standard even existed)
Gold-border World Championship decks (1997-2004).
Other decks from World Championships after 2004, either top 8 decks or undefeated in standard portion

Conclusions:

Still unaware of Academy, Memory Jar, and Necro, because they weren’t part of World Championship top 8s, but this is the beginning of my internet research into old decklists.

The combo deck that never faced a counterspell wins. Just fast enough to beat a bunch of aggro decks, and one other combo deck.