Our preference is the Universal Hotels, but they're not practical, when only going to WDW. We stayed @ Holiday Inn Sunspree last summer. It was fine. It was actually nicer than I expected from the reviews I read. The room was clean, & they were great about our mini-pinscher. If you stay there, don't eat the breakfast buffet. It was horrible! We've booked Orlando Vista Hotel for May. This will be our 1st time staying there, so I don't know what to expect.
I know what you mean about not leaving your 4-legged baby home. We left our's home, when we stayed at Dolphin in Oct. As you can see, we're back to staying offsite.

If your stay is after Oct. 21st, the new Hilton @ Bonnet Creek is supposed to be pet-friendly. That's where we'll be staying in the future.
Wherever you end up staying, please let us know what you thought.
ETA: It looks like the Waldorf Astoria will also allow pets. I'm excited to have some upscale, pet-friendly options near WDW. It's about time!