I have used a ticket consolidator for international travel and she saved us several hundred dollars per ticket.

I often check AAA packages for places like Disney World or Hawaii, as they can have some real deals. We used www.buildabettermousetrip.com for our last couple of Disney World trips. They're not a TA, more of a consulting service which helped us buy the right tickets and not get stuff we weren't going to use.

Domestic travel - I do most of the research myself for airfare, hotels, and car rental.

Booked my last two cruises through United Airlines travel services. The price was the same as I found on my own but I also received frequent flier miles, which was a nice bonus. I've also found small discounts on car rental this way.

I would like to try taking an Amtrak train sometime but their website completely stresses me out. Train travel seems to always cost twice as much as air. I wonder if a good rail TA would be able to help me out.