Yep. Splitting meals at WDW is a great way to save money. Heck I get kids meals alot. But, even an adult burger and fries..at cosmic rays the wife and I have split many times.My ex and I used to split all the time. At Cosmic Rays in MK the half chicken combo or Chicken and Ribs combo are both big enough for 2.
In Downtown Disney I like Wolfgang Puck Express a lot, and you could split a number of things there.
My other trick if I'm trying to save money or calories is to get a kids meal.
In general, I think you can split MOST of the QS meals in WDW. The few that immediately come to mind is Chicken and Ribs @ Flame Tree in AK, Fish and Chicken meal @ Columbia Harbor House in MK, Shwarma Platter @ Tangierine Cafe in Epcot, Wolfgang Puck Express in Disney Springs
Those are the 2 QS meals that popped into my mind as well.At EP we split the shwarma platter at Tangierine Café, and at AK we split the sampler platter and the rib dinner.