from recordholders.org

The first world championship was held on 5 June 1982 in Budapest. First place: Minh Thai (USA) 22.95 sec.
Record time for the 4x4x4 cube (Rubik's Revenge): 1:00.38 min by Yuki Hayashi (Japan) at the Kyoto Rubik's Cube Contest on 10 July 2005.
Record time for the 5x5x5 cube: 2:08.45 min by Lars Vendenbergh (Belgium) at the European Championships 2004 in Amsterdam
One handed record: 25.95 sec by Christopher Hardwick(USA) at the US Championships on 10 July 2004.
With feet only: 4:06.68 minutes by Will Arnold (USA) at the Caltech Spring Tournament on 16 April 2005
Blindfold, fastest time: 2:41.54 minutes (including memorising), Leyan Lo (USA) at the Caltech Spring Tournament on 16 April 2005
Blindfold 4x4x4 cube: 19:54 min (including memorising), Dror Vomberg (Israel) at the European Championships 2004 in Amsterdam
Blindfold 5x5x5 cube: 2:34:36 hrs (including memorising), Stefan Pochmann (Germany) at the European Championships 2004 in Amsterdam
The fastest time for solving 2000 cubes was achieved by Jess Bonde (Denmark). He solved 2000 cubes in 22:16 hours on 16/17 Dec 2002 in Arhus.
The largest Rubik's Cube was built by Daniel Urlings (Luxemburg). Its edges are 3.52 m [3 yd 2 ft 7 in] long.
The most expensive Rubik's Cube was the Masterpiece Cube, produced by Diamond Cutters International in 1995. The actual-size, fully functional cube features 22.5 karats of amethyst, 34 karats of rubies, and 34 karats of emeralds, all set in 18-karat gold. It has been valued at about US-$ 1.5 mio.
The youngest person who solved a Rubik's Cube was John Ismael Ugelstad (Norway aged 5 years 117 days) who solved three standard Rubik's Cubes on 28 Dec 2004.
3x3 Fusion (Siamese Cube): 1:10.96 min by Kenneth Brandon (USA) at the World Championships 2003 in Toronto