The 2000 election was definitely stolen, while Ohio most likely was.

Bush "won" Florida with 537 votes. Considering the fact that blacks were 1,000 times more likely to have their vote invalidated - I would say it was stolen. Here is a brief summary of the issues by Greg Palast - BBC journalist.

YouTube - Election Rigged for Bush

They PURPOSELY and falsely accused tens of thousands of blacks of being felons purging them from eligibility and turned away at the polls.

Programmer who testified in court explaining how vote-rigging was done in Ohio and Florida.
YouTube - From The Programmer's Mouth: How The 2000 Election Was Fixed

More info from Palast:
YouTube - How George W. Bush Stole The 2000 Election - Part 1 of 2
YouTube - How George W. Bush Stole The 2000 Election - Part 2 of 2