EPCOT is by far my favourite park. By miles and miles-- by lightyears, even, it's my favourite park.
In Future World, I love Ellen's Energy Adventure because it's such a classic ride to me. Plus, Ellen DeGeneres+Bill Nye the Science Guy=WIN. Mission: Space is a ton of fun! And don't forget Spaceship Earth-- the ultimate thing to do when you're hot and want to listen to Dame Judy Dench tell you about the history of the world (honestly, it's a pretty awesome ride). Don't forget Soarin'! That's so much fun!
In World Showcase, there's THE FOOD! I'm a food lover and I never miss a trip to WS for food. Frozen tea in China, Kaki Gori in Japan, Crepes in France, the list goes on! Plus, there's something at every country. There's Chinese Acrobats (at...one guess....China) that are really awesome to see. The boat ride in Mexico isn't that great, but it's air conditioned in the pyramid (I remember you saying you were going in July). Norway has a pretty neat boat ride, too (and a great bakery). Germany has an awesome bakery and Biergarten is absolutely delish! Italy has the World Showcase Players and their version of Romeo and Juliette (this is a must-see for my family). The U.S. has a really inspiring movie (I'm not particularly patriotic, but I like the show here). Japan has the most awesome store ever and my second favourite restaurant-- TEPPAN EDO! So yummy! In Morrocco you can meet Aladdin and Jasmine and get a henna tattoo. France has a pretty neat movie and an acrobat (and a bakery...). The U.K. has another set of the World Showcase Players with their rendition of King Arthur and the Holy Grail (GRAIL!GRAIL!GRAIL!HUH!) and this show is so funny you really should catch it! Canada has a CircleVision film with Martin Short (there's another CircleVision film in China). Also in Canada is Le Cellier-- my all-time favourite restaurant ever.
Then at night, there's IllumiNations: Reflections of Earth (in my head, I sounded just like the guy who announces that at the park...is it James Earl Jones?). This is my favourite currently running Fireworks show. It's so amazing. Make sure to stake your claim on a seat forty-five minutes to an hour prior, though!
So yeah, there's no shortage of things to do at EPCOT.