Epcot for Adults, easy sell. For Teen boys, difficult, but getting easier.
For the boys, I'd direct them to some online descriptions of Test Track, and especially Mission: Space. Getting on the newest, best, baddest ride in America should interest them. Also, Illuminations should have major appeal to teenage boys. Lot's of fire, explosions, and lasers. And Innoventions, basically a sales gimmick for the hi-tech industry, seems to always be filled with teenagers. Lot's of stuff to play with. THEY could get lost in there for hours.
As for Adults: This is one admitted fanatic's opinion. But Epcot is the Mecca of Disney to the over 30 set. I personally ran out of steam with coasters and other thrill rides about a decade ago. Amazingly, I even find Space Mountains stirs me up now. But Epcot provides tons and tons of more adult-oriented entertainment (Disney style, mind you, not the x-rated variety).
Futurworld holds a what I think is a neat aquarium (some, in fact many would disagree, but I love it), several longer educational yet entertaining attractions (such as Ellen's Universe of Energy and Spaceship Earth), and if you still want a little "action," Test Track is a neat feature (I know nothing of Mission: Space, but it's supposed to be a dandy). Body Wars also fits this bill.
World Showcase is a gem. One can visit several countries in one day, literally. The architecture is phenomenal. The countries were built with detail in mind. Mexico and Morroco are my favorites, you'll soon have your own. There are several easy rides (such as Maelstrom in Norway), and great movies in China, France, and Canada (we just love O' Canada in circlevision). There is almost constant entertainment, such as Off Kilter and a Beatles-like band in the UK, drum shows in Japan, jugglers in China, and the Mariachi Cobre in Mexico, an incredible act I could listen to for hours (try and ride the Mexican boat ride, El Rio Del Tiempo, while the band is playing). El Rio Del Tiempo is a surprising ride. Almost gaudy to a fault, it somehow works. It's been described as a scale model of It's a Small World, Mexican style.
Then there's the food. Epcot is the restaurant capital of Disney. Some of Disney's best restaurants are located here, certainly the greatest selection. I personally love Le Cellier in Canada; the Rose and Crown in the UK for Illuminations; the Biergarten (Germany) and San Angel Inn (Mexico) for lunch; and I pity the fool that never tries a Trapper Johns Beaver Tail (Canada) for a sweet snack.
Finally, and this is soley my opinion mind you, Illuminations is the best fireworks show in Disney. Lasers, a fiery barge, a globe made of TV sets, and some very incredible music make it just awesome. And if you wind up in Disney in the off-season, it's held every night regardless of crowds. And Epcot stays open until 9 PM every night, also in off-season, to accommodate this show (and no doubt fill the restaurants).
A final word: if you're going IN SEASON, when it's hot and crowded, in my opinion Epcot is simply built better than the other parks for hot, sloppy days. There seems to be more shade. Although huge, the park is walker-friendly. My wife tells me there's more bathrooms (I never notice such things). And with it's enormous amount of cultural attractions, nothing ever seems to get obnoxiously full except Test Track (I'm assuming for the next couple years, Mission:Space will buck this trend). If there was housing, I'd simply live in Epcot.
Did I sell you? Because if not, there's always the topless sunbathers in the French Pavillion. And if we're talking a guy that would be interested by this, you can also explain to him about the wall-to-wall beers of the world.....
Pat
