BurtonAvenger summed it up pretty well in one sentence.
But let me elaborate a bit more on what he means by that. I've been lucky enough to have been in both places, so I'm not just shooting from the hip. I assume that since you're asking this in a snowboard forum that we're talking about going snowboarding....so let's limit the timeframe to a 5-month stretch from Dec through April.
Switzerland is flat out gorgeous. It's flat out expensive too - now more so than ever with the crappy dollar/euro exchange rate. Most Swiss speak english, but still depending on which part of the country you'd visit you'll get a heavy dose of either french or german. Food is great. Beer is great. Late night discotech raves can be quite memorable. Snowboarding - to get to the heart of the matter - can be really good. You've got more freeride / big mountain orientated resorts as well as several with world class pipes / parks. If there's not good snow early on, the trip could be less about snowboarding and more about the "vacation" (i.e. drink, eat, start smoking if you don't already, and party with eastern euros till the sun comes up).
Alaska is an ENTIRELY different experience.
And if you're talking about Alaska, I guess you'd separate that into trying to go to a pretty darn good resort like Alyeska versus going for heli time. If you're talking a place like Alyeska, Snowolf hit a lot on the head. It's an awesome freeride mountain that gets a poop load of snow. Dec thru like mid Feb can be downright nasty with big storms and reduced daylight. The lodge right there is pretty nice with all the amenities. Girdwood close by has some good local spots, but if you're looking for alaskan cougars and/or some semblance of night life, you'd have to head into Anchorage. Even there, we're not talking euro style / whistler / "resort" community. It's fairly WT (in a good ol' boy way), and the discussions at the bar might be about fishing, hunting, snowmachining, drinking, etc.
But if you're really looking for a memorable time, are ready to rough it a bit, and have the ability to ride steep and deep terrain, getting laps in a heli in AK has ABSOLUTELY NO COMPARISON. It is the mecca of big mountain freeriding. Go in good riding shape. Go prepared for little to no amenities. Don't go unless you've taken an avalanche course, know how to dig out your buddy, and have at least a beacon, shovel, probe & good pack. Go with a crew that fills one heli so that you're not an odd man out. Go with people at roughly the same riding ability. Go prepared to do plenty of day drinking on a "down day." Go prepared for mulitple down days. Don't go for less than 7 to 10 days. Go during March and April.
I spent most of this past April up in Haines (my 3rd time). I've got over a dozen blog posts about my trip archived on the link below, just scroll down and you'll see them all under "Chappy's Daily Alaska Heli & Sled Lovefest"...
Porters Tahoe Blog
Slightly more than just two cents worth, but hope it helps.....