I have several vendors that have checked the LLC box and noted that they are a "corporation" for the tax classification, not disregarded entity or Partnership. If they are a corporate LLC, do I send them a 1099 MISC?

See:
Instructions forForm 1099-MISC (2009) (http://www.irs.gov/instructions/i1099msc/ar02.html#d0e102)

Under reportable payments to corporations.

If they are in fact a corporation, then NO Form 1099-MISC is required.