The BEST QS places are:
MK: Cosmic Ray's, Columbia Harbour House, Captain Cook's (in Poly).
Ep: Boulongerie Patisserie, Mexican Fast Loaded Nachos, Liberty Inn, Sunshine Seasons.
AK: Flame Tree BBQ
HS: Pizza Planet
However, Keep in mind that after a long day of walking and excitement at WDW, the portions at any of these places are most likely not large enough to share. For that, you may need a TS, unfortunately.