Looking to go to either Glacier, Bryce or Zion National Park with my husband and 2 teenage sons - any recommendations?

How much time Janie?

Actually, it doesn't mater that much. Hands down, without question I would do Zion and Bryce together (and I have been to Glacier as well). If you have a week, I would add in the North Rim of the Grand Canyon if you have never been.

This from a guy who did it recently with his family including 2 teenage sons.

I have been to Zion and Bryce, but not Glacier. It really depends on a red rock desert atmosphere versus the mountains. Zion has some great hikes (the Narrows) and so does Bryce. I am going back to Utah this week for the second time in three years, because for me it can't be beat for scenery. We are going to Capitol Reef and Escalante Monument. Some day I would like to see Glacier though.

Glacier is a hiker's park. To see the best parts of the park, you must leave the road. The Sun Road is Special!
But I don't think you get the full flavor of the park unless you get out on the trails.

If you elect a mountain, glaciated park, be sure to venture to the Canadian side.
If you have a full week, consider a drive as far up as Banff for more scenery.

Bryce and Capitol Reef are dry canyon parks. Zion is a hot, dry canyon park.
Yes here is a creek at the bottom of some of those places, but they are dry areas.

It is hard to select because they are so different. I love them all.
I think it depends on what you want.
I also hate to think that I would not have seen all of them.

If I were going in August, I think I would select Glacier. If September or later, I would select the canyon parks.

Glacier is my favorite NP, but I agree that it is basically a hiker's park, and may not be too exciting for teens. I'd vote for Bryce and Zion so you can fly into Vegas and give the kids some tacky tourist stuff in addition to all that nature. Unless your kids are unlike mine and enjoy hiking as much as my husband and I do!

Zion and Bryce together. I think it would be more appealing to your children do to the variety of activities you can enjoy at these two parks which are close in proximity. I think they would really enjoy hiking the Narrows in Zion (if its safe to do so now...)

bob brown and karens have it right. glacier is a hikers park, if you aren't hiking you only need a day or two to tour going to the sun road and other areas of the park. there are easy hikes but very few little circuit nature trail types. i wouldn't want to scare away a non experienced hiker from glaciers beauty. but you really need to like hiking to really experience it.

Bryce and zion may be more the ticket you have short duration hikes, you can have horseback rides in bryce that are really neat. you can hang out in the virgin river at zion.

weather wise, bryce and zion will be hot in the summer and dry (well except for the weeping wall and narrows hike in zion) that's where glacier's climate would be better in the summer. october is awesome in utah. october has rain and snow at glacier!

i'll throw one other thing in the mix. have you thought about canyonlands and arches in moab? there is tons to do there for teenagers, mountain bike tours, river floats etc. both parks have short easy hikes to interesting things.

and moab is more of a town for walking around at the end of the day and more restaurant choices than either of the other places you would be at bryce, zion or glacier