Years ago, when we would go to one of the fireworks shows, we'd end up standing where ever we'd happen to be. We were continually trying to get a better look over the heads of all of the other guests. Illuminations was especially hard to see, since the globe is out in the middle of World Showcase Lagoon.
Now, I like to travel cheap, but I'm willing to pay a little extra to get the most out of my vacations. My favorite place to watch "Illuminations: Reflections of Earth" is the Rose & Crown sitting at an outside table! The outside seating area is right across where the globe is positioned during the show! You'll need to make a reservation.
During "Wishes" there's a dessert party that's held during the show on the Tomorrowland Terrace! The party starts one hour before the start of "Wishes." I also recommend making reservations since it's so popular.
If you don't want to spend the extra money for a dessert party, I'd recommend viewing the fireworks at the rose garden on the side of Cinderella Castle just outside Tomorrowland. You'll also have a really good view of Tinker Bell flying over head during the show! I'd also recommend getting there early to stake out a good place to watch the fireworks.
(407) WDW-DINE (939-3463) to make advance reservations.