I lived and worked in Glacier for 8 summers when I was younger, and still don't feel I spent enough time there. Everyone's tastes are different, but for my money it easily beats the heck out of Vegas. (Or of Yellowstone, for that matter.)
If you decide to go for it, and need any additional ints on lodging/dining/hiking/whatever, definitely let me know.
I booked the Mountain Pine Motel for my stay, and plan on taking one of the day long Red Bus tours the first day to acquaint myself with the park. On the second day I will probably do the Garden wall hike, which will take me all day as I will probably be stopping every few steps to take pics. I've just started reading a few books about the park and haven't decided what I'm going to do the other 2 days I'm there. i may drive around the southern end of the park (rte. 2) and come back on the Going to the Sun rd. I have until the end of July to make up my mind.
The Mountain Pine motel will be fine, and is one of several Mom-and Pop places in East Glacier. There are a number or restaurants there, too -- I generally eat at the Villager when I'm over that way.
The Red Bus tours have a lot of appeal to first-time visitors, and the busses themselves are definitely fun to ride. I don't always recommend it to people, though, because the caliber of the driver/guides is really inconsistent. And the experience you get also depends a lot on the fellow passengers you end up with ... sometimes they're lots of fun, sometimes not.
The Highline (garden wall) trail is definitely the classic day hike in the park, with lots going for it, including great views and near-guaranteed mountain goat sightings. You also get to see one of the Great Northern's old backcountry chalets, which is extremely cool. And there's also much less uphill than most other Glacier day hikes.
Other day-long Glacier hikes I really like include Siyeh Pass and the Dawson-Pitamakan loop. For folks who are really in shape, Gunsight Pass can't be beat.
My favorite part of the park these days is actually Polebridge, a funky little place out in the middle of nowhere, with a good restaurant and the best bakery in the state. A long ways from anywhere else, but you get away from most of the tourists and get so see a bit of "real" Montana. Great country up there.
But wherever you go, I'm sure you'll love it!