It depends on what you are doing your last night. If you are looking for something good to eat with a great theme but not to crazy I'd suggest 'Ohanas. It is festive without being hyper-active. If you are looking for hyper-active go for Whispering Canyon or Chef Mickey's.
If you are looking for something elegant try California Grill, especially for the fireworks or at sunset, or Narcoossee's, again for the fireworks.
For something a little more affordable and laid back try Shutters at Old Port Royale.
If your looking to stay in the parks the choices are about endless.
At MK I like Crystal Palace. EPCOT has a ton of great stuff, but the Rose and Crown for Illuminations is a great way to end a vacation. DHS has The Brown Derby or for something more casual try Mama Melrose. If you are doing AK I'd recommend waiting to until after the park closes and go to a resort.
Finally a personal favorite that you can easily do after the parks is Ragland Road at DTD. Great burgers, awesome entrees, and outstanding entertainment.