Generally speaking, Orbitz.com and CheapVacations.com always beat out the other travel sites for us coming from MSP. And that is BEFORE the extra $150 off each site has, both sites are always the exact same price, they must be owned by the same parent corporation.
We always use Orbitz. This year we booked Oct 26-Nov 3 out of Springfield MO for under $2K. This was $300 less than last year and we have better flight times.
Just booked 5 nights with air over the Halloween weekend via Orbitz and with the promo code and even including insurance it was still less than $700 per/person. Great deal.