As mentioned earlier, don't forget about the restaurants at the resorts!! Since you're staying at All-Star, you'd probably want to check out a resort restaurant that is near a park (easier to get to, as direct resort-to-resort transport is non-existent.). So, my suggestions:
1. Via Napoli in EPCOT. It is a must do on every trip, however it might not be the "date night" setting you're looking for. I'd check out menus AND inside pics to get a feel for the atmosphere.
2. The Wave. It's inside the Contemporary Resort, which is a 2 minute monorail ride away from the Magic Kingdom (which everyone else agreed you cannot miss.) The food is awesome...it's a hidden gem. It's organic, local, etc... And has a wide variety of options. If you're planning to stay at the parks from open-til-close, it would be a great place to relax outside of MK for an hour, but still be close. If you're planning on going back to your room midday to relax, you can easily go there before you head back to MK for the night.
3. Feeling adventurous? Sanaa at Animal Kingdom Lodge-Kidani. If you're looking for a little spice! It's has the best atmosphere...plus you can tour AKL resort before and after.
4. Finally, Kona at Polynesian. Ok, do it has the least impressive atmosphere of all I've listed and the food is good, not excellent IMO....BUT...you have an excuse to hang out at the Poly, which has the best atmosphere on property!
Ok, so I basically just listed all my ADRs for my upcoming trip. But hey, these are the places I like!
I wouldn't try to eat at HS for what you're looking for...and I would skip AK altogether. Maybe. And I'm not looking to re-plan your trip, but....
You didn't mention when you're arriving or leaving. Reason I mention this is that a 3-day pass is $560 for two people. A 4-day pass is $595! That's only $35 total for an additional day. So, it you have a later flight on your last day, you might want to consider making that your AK day, morning only. Or if you arrive earlier the first day, you might want to check out HS for an evening.
Remember, you can do it all. Pick a couple of must-dos, per park, and plan around those. Everything else will be a bonus. Enjoy!!
come on, to even think about skipping the castle AND WISHES is such a horrifying thought! The OP should be thanking us! 
We're planning on visiting the aquarium though and maybe stopping in for a dessert.
Then, for the MK and AK days, we get there early and leave around lunch time (or after we eat at quick service in MK at Cosmic Ray's), go relax at the resort for a few hours (this is vacation after all!!! No sense running all the time or you go home without being refreshed), and then go back to whatever resort we were checked into for the day for some more rides that we could not do earlier or for fireworks or food. We also do the same for HS days usually. But Epcot, you really need all day or 2 half days. So, you have 5 total days but if you are coming in on the 22nd and leave on the 26th, you really have 1 half day when you arrive and 3 full days since the day you leave, you don't want to think about going to parks since you have to check out by 11 am. They can store your luggage at the checkout but the most I would do is go to Downtown Disney if you have a later leaving time. So, what I would do, if you don't want to go to MK for long is go there the night you get in to start the trip. HS has the most thrill rides, like Tower of Terror and Rockin Rollercoaster. AK has Everest which is awesome too. Epcot has Mission Space which has a gentle level if the Gforce will get you sick and of course, the world showcase which we LOVE!!! Have fun! We were going in Sept but now hopefully we are going in Feb for our 6th anniversary!
