I used to watch Wishes from the Tomorrowland bridge, but that changed with the Celebrate the Magic show. It's really best to see that from right up close, so I get as close to front and center on the castle as I can. Then I just drop back next to the Partners statue for Wishes - perfect!
For years I've enjoyed IllumiNations from right in front of the Canada pavilion, right across from the steps leading up into the pavilion. There are some trees there, and it looks like your view would be blocked, so large crowds don't mass there. You might have 2 or 3 people in front of you, but it's still an excellent spot for viewing (and the trees don't block anything!).