Originally Posted by
javabytes
Delta is the best site to book travel, but a poor choice for searching and pricing flights. Use ITA, Google Flights, Kayak, etc. to find your flights and price them. Then go to Delta to book. If the Delta website doesn't offer you the options you want or the prices you found elsewhere, try a multi-city search and piece it together segment by segment, or call in.
I would add to this that sometimes I've been unable to replicate my desired flights on delta.com, so I've used Google Flights which (usually) will generate a link to book on the airline website. That should pull up the exact flights. Additionally, Hipmunk can be used to select flights and then redirect to delta.com. Hipmunk is a little clunkier than Google Flights IMHO, but it has the added advantage of accepting ITA Matrix syntax because, I if understand correctly, it uses the ITA matrix back-end.