I'd say it's pretty close, but I'd choose Epcot. There's simply more rides. They're not the most popular, but my kids have always loved Universe of Energy, Gran Fiesta Tour, Imagination and Nemo (I like them all, too, even though it's unpopular!). I like having all of those rides (along with SSE if it's not the morning) that you can hop on without a huge wait. If your daughter is tall enough for Splash and BTMRR (based on your other thread), then she'll be tall enough for Test Track and Soarin'. They are both very very solid rides. Those two are also not that intimidating... Soarin' especially.
Here's my list for each park:
Epcot:
SSE
Soarin'
Test Track
Nemo
Imagination
UoE
Gran Fiesta Tour
Living With the Land
DHS:
TSMM
Star Tours
ToT (very intimidating from the outside, though)
GMR
Muppetvision
Disney Junior
VotLM
BatB