How long are you visiting for? 2 weeks? If so, you might want to consider leaving Busch Gardens for a future trip. Unless you absolutely love water parks, I would say that Wet 'n' Wild could be missed, but as you're staying on I-Drive, you can probably squeeze it in somewhere.
Magic Kingdom
Jungle Cruise
Pirates of the Caribbean
Splash Mountain
Big Thunder Mountain Railroad
Haunted Mansion
Mickey's Philharmagic
Space Mountain
Buzz Lightyear's Space Ranger Spin
Carousel of Progress
Wishes
SpectroMagic. We seldom bother with parades - I don't like all the jostling for position and hanging around for ages beforehand - but we've seen them all at least once and Disney does them well. Share a Dream Come True, the afternoon parade at MK, is my least favourite of those currently on offer. SpectroMagic is hugely popular and, other than the very busiest times, is only shown a couple of nights a week (unlike Wishes which is performed every night). My favourite place to watch the MK parades is Frontierland. We arrive at least an hour beforehand and grab the rocking chairs on the verandah of the Liberty Tree Tavern. We then just chill out and people-watch until parade time.
Epcot
Spaceship Earth (but don't do it as you enter the park - you need to experience the more popular rides first before they get too busy)
Soarin'
Test Track
Ellen's Energy Adventure. This is a really long ride/show (around 45 minutes), so bear that in mind when fitting it into your schedule.
Honey, I Shrunk the Audience
Maelstrom
El Rio Del Tiempo
Mission: Space (I've never done it, but it is a headliner)
Living with the Seas (the pavilion has had some new attractions added recently and is undergoing further refurbishment, so will probably be worth a visit by the time you go)
IllumiNations. Don't join the crowds on World Showcase Plaza. There are plenty of better spots around the lagoon. Just make sure you haven't got trees obscuring your view.
Over the years, Epcot has become our favourite park, and many of the things we choose to do now would probably not appeal to a first-timer.
MGM Studios
Rock 'n' Roller Coaster
Tower of Terror
The Great Movie Ride
Who Want to be a Millionaire - Play It!
Indiana Jones Epic Stunt Spectacular
Star Tours
Backlot Tour (including Catastrophe Canyon)
Lights, Motors, Action!
Muppet Vision 4D
Fantasmic
Disney Stars and their Cars. We saw this for the first time last May - we'd never bothered before and it's surprisingly good. Get a spot right by Star Tours where the parade starts. Get there in good time and make sure you stand directly behind one of the brass lines (inlaid into the paving) and no-one will be permitted to stand in front of you (the CMs will move along anyone who tries).
We also like Adventures of the Little Mermaid and the Beauty and the Beast show, but I guess they're really aimed at children. Having said that, I know more than one guy who finds they have certain attractions!
Animal Kingdom
Expedition Everest
Kilimanjaro Safaris
Dinosaur
It's Tough to be a Bug
Festival of the Lion King
Kali River Rapids
Mickey's Jammin' Jungle Parade. This is Disney's best parade, IMHO. It starts and ends next to the entrance for Kilimanjaro Safaris, so we always grab a spot on the low walled area in front of the rest rooms opposite Pizzafari (you can then watch it twice if you want to). As always, you need to arrive in good time to get this spot.
AK is another park which grows on you and you start appreciating other aspects the more you visit. If you like animals, the lesser attractions are well worth a look - Maharajah Jungle Trek, Pagani Forest Exploration Trail and the Oasis. It took many visits before we discovered the trails around the Tree of Life - a quiet and relaxing break with hardly anyone else around.
Universal Studios
Revenge of The Mummy
Shrek 4D
Terminator 2 3D
Men in Black
ET Adventure
Jimmy Neutron's Nicktoon Blast
Earthquake
Jaws
Back to the Future
Fear Factor Live is a new show, which we've never seen, but I guess it would appeal to you and your brother.
Islands of Adventure
The Amazing Adventures of Spider-Man
Incredible Hulk Coaster
Dr Doom's Fearfall (you wouldn't get me on this if my life depended on it, but it is a headliner)
Popeye and Bluto's Bilge Rat Barges
Dudley Doo-Right's Ripsaw Falls (I really don't like this, but again, it is a major attraction)
Jurassic Park River Adventure (another which I've never plucked up the courage to try)
Duelling Dragons
The Eighth Voyage of Sindbad
Poseidon's Fury
CityWalk is also a destination in itself and, as you have to pass through it to visit either park, you may as well take a look around. I recommend lunch at the Hard Rock Cafe.
Sea World
I haven't done any of the thrill rides here, but they're all headliners. The Shamu Show is the number one must-see, but lots of other attractions, shows and exhibits are good, too. It's a really nice park, especially since they've added the new Waterfront area. The news shows are also supposed to be fantastic - I must get around to seeing them! Don't miss the Anheuser Busch Hospitality Center - free beer!
As you're going to have a lot to fit in
* make sure you avoid the Extra Magic Hours days for onsite guests at the Disney Parks (they're always significantly busier);
* aim to arrive at the parking lot at least half an hour before park opening - you can pack in a lot of attractions in the first couple of hours before the parks start to get really busy;
* make full use of FASTPASS at the Disney parks.