My first suggestion would be to check out the menus (including prices) at
www.allearsnet.com This way, if anyone makes a suggestion, you can check out the menu to see if it can fit within your budget.
If you can swing it, I'd suggest Rose and Crown in Epcot. It's where I popped the question to my wife. With a little bit of secret begging, they gave us a table on their patio, so we could watch the fireworks while seated (plan ADRs accordingly, around 8 if possible). I had flowers delivered a few mins before Illuminations, and actually proposed just before the show began. Great night. (Usually) a fairly romantic setting.
Something else that has its charms and isn't as expensive is just grabbing a bite along the Boardwalk while people-watching, or getting some to-go at Beaches & Cream at the Beach Club and THEN walk down the Boardwalk. Olivia's in OKW has some tasty food, and usually isn't too busy, because it's so out of the way, only people staying at OKW usually go there. And while not as fancy as the Cali Grill (and there will assuredly be more kids around), you may want to consider OHana's in the Polynesian. Time your dinner to hopefully coincide with fireworks, and see if you can't swing a table by a window overlooking the Castle.
Finally, again, not the most romantic setting, but consider the Trail's End Buffet at Fort Wilderness. Not for the setting of the meal itself, but afterwards, ou can walk along the lake, maybe see the Electrical Water Pageant, OR enjoy the campfire singalongs and free movies ('smores optional). It can be pretty cozy, especially if it's not too hot. AND, unless you don't want to be "too tired" at the end of the night when you get back to your room, try to arrange to go to Trails' End during a night when they have late EMH at the Magic Kingdom. You can spend some time in the MK, ferry over to Fort Wilderness, eat, catch the Pageant or a movie, then ferry back just before closing, get a wristband, and start running like little maniacs throughout the MK.
I don't want to suggest any more, because I have zero idea what your budget is like, and I don't want to recommend places that make me look like a jerk for suggesting them. Again, check out the menus as other people leave their opinions, and then you'll get a better idea of what's right for you.