Plenty.
First off, it has the world's highest Starbucks. If that's not enough to recommend it, well, here's more.
If you make and keep reservations at the Top of the World restaurant on the 106th floor, you get to bypass the elevator line and ride to the top of the tower for free. Some people consider this restaurant to be overpriced, but the view's the thing. It's so spectacular (the room rotates like clockwork every 80 minutes) and romantic that whatever you order is not only good enough, but well worth the cost. Appetizers are in the $14-$22 range; entrees are mostly meat and fish, from chicken ($32) to filet mignon ($42) and New York steak ($48). Sides dishes are all $7 and desserts are relatively inexpensive at $8-$10 (try the signature Chocolate Stratosphere). You can request a window table, but there’s usually a wait, so you might want to make your reservations a little earlier than you plan to eat. You can go up a floor to the bar and lounge on 107 while you're waiting.
Or you can go up more floors to the indoor (Starbucks) and outdoor observation decks. Watching the three thrill rides at the top is a good way to pass the time; if you're of a mind, you can also ride them.
The Big Shot is perhaps the most ferocious thrill ride on the planet. It flings you up the needle to almost the top of the tower at 4 G's of force, then drops you so hard and fast that you experience a moment of zero G (essentially, you leave your stomach at the apex, while the rest of you plummets back down to the tower). The Big Shot alone is worth the whole trip, assuming you’re into thrill rides.
You can save your money on the two other rides. X Scream dangles you over the edge of the tower on a track; though the sensation is supposed to simulate rolling off the building, it's more like just sitting there. Insanity is a centrifugal ride where you're spun, around and around, so fast that you wind up horizontal to the Earth. Just watching it makes us nauseous.
So those are the things to do. If you're paying admission to get to the top of the tower, it'll run you $9.95 adult; $6 children 4-12, locals, seniors, and hotel guests. The rides are $8 each. And there are various packages: all-day unlimited $29.95; admission and three rides $23.95; admission and two rides $19.95; admission and one ride $15.95. Look for discount coupons good for a few bucks off, which are pretty common; LVA members get 2-for-1 admission and rides. The tower hours are Sunday-Thursday 10 am to 1 am; Friday, Saturday and holidays 10 am to 2 am.