The best way to decide which candidate is the best for voters is to have open access to candidates. A debate is a perfect way for voters to get in touch with candidates at the time they are running for office. Of course we should have access to our candidates because that is how we can help determine which candidate we want to vote for.
Every election season it amazes me how much corporate money is funneled into the coffers of both the Republican and Democratic parties. It makes it impossible for a 3rd party candidate unless they are a billionaire (i.e. Ross Perot, Ralph Nader) and even then they are a long shot at best. We should allow every viable candidate the opportunity to debate on free television and should disallow all campaign fund raising and campaign ads altogether.