In case it's helpful to anyone, here's what we accomplished in a 1-night trip to Niagara Falls, arriving the day before Easter. We traveled by car from upstate NY.

Arrived 8AM at Rainbow Bridge (toll on US side before crossing to enter Canada); no line at border. We traveled with our 2 daughters (14 and 9) and one of their friends, for whom we had a passport and a notarized letter saying we could travel with her, and the border agent asked for the letter, so I'm glad we had it.

After breakfast at an IHOP and a stop at an ATM machine, went to Whirlpool Aerocar then Whitewater Walk. No lines or crowds at either place, either due to the time of day (near opening time) or time of year (near opening day for at least one of these). All of us enjoyed both of these.

We drove back to town for some cheesy tourist stuff on Clifton Hill: the Ripley's museum was actually pretty good, and again was something we all enjoyed. Lunch was at Wendy's with a view of the falls (we went for the view, not the food), though the view will soon be obscured by leaves as they fill in, I think. Dracula's Haunted Castle was after lunch - unless you have a heart condition, go for the "maximum scare" option, as I think it would be pretty lame otherwise. There was much screaming.

Our hotel for the night was the Marriott Fallsview, where we got a deluxe fallsview room (fake fireplace, great view of both falls by day and night). The price printed on the door was $899, which I doubt anyone ever pays; we paid $199 (by calling the hotel directly). I highly recommend a fallsview room, and the Marriott was great in every way. Valet parking was $20/night, but when I checked out and told them it wasn't on my bill, they said it was on them. OK by me!

After checking in, we walked down to the top of the Canadian Falls to gawk for a while. Note that many of the Fallsview area hotels are up on a bluff; to get down from there to the falls you either take the funicular ($2 a trip, I think) or you take a long walk around the bluff -- the funicular was closed, so we had to walk, but the weather was great (nearly 80 F). We took the Journey Behind the Falls, which was well worth it, then walked back up the hill to dine at Romano's Macaroni Grill. Food was fine.

The kids hit the hotel pool after dinner, while my wife and I had a drink and gawked out the window at the illuminated falls -- quite a sight, by day or night.

Breakfast the next morning was a buffet at the nearby Country Chalet: $6.99, not including drinks. Not a huge selection, but adequate and efficient. This was followed by the "4D" movie near the base of the Skylon Tower; that was about the only thing we did on this trip that I wouldn't really recommend, though it wasn't awful. We then checked out, crossed the Rainbow Bridge back to the US (about 30 minute wait at the border), then visited Goat Island, seeing both the falls from the top side and taking the "Gorge Trip" to the Cave of the Winds so we could gawk from near the bottom of the falls.

We were too early in the season for the Maid of the Mist or jet boats, both of which we probably would have tried if we could, but it was a great trip, and everybody enjoyed everything, with the exception of the adults not thinking too much of the "4D" movie. But we did strike a pretty good balance between appreciating the natural wonders and sneaking in a couple cheesy touristy things for the kids.

Feel free to post questions if there's something I can expand on.