Oh, what's the Higgs Boson particle, you ask?
The Higgs boson is an elementary particle in the Standard Model of particle physics. First suspected to exist in the 1960s, it is the quantum excitation of the Higgs field, a fundamental field of crucial importance to particle physics theory.
Stole this from an excerpt by Stephen Reucroft from ScientificAmerican.com (thanks bruv!):
Over the past few decades, particle physicists have developed an elegant theoretical model (the Standard Model) that gives a framework for our current understanding of the fundamental particles and forces of nature. One major ingredient in this model is a hypothetical, ubiquitous quantum field that is supposed to be responsible for giving particles their masses (this field would answer the basic question of why particles have the masses they do--or indeed, why they have any mass at all). This field is called the Higgs field. As a consequence of wave-particle duality, all quantum fields have a fundamental particle associated with them. The particle associated with the Higgs field is called the Higgs boson.