We're seniors (81 & 76) travelling on our own, by car. Spent 3 nights at "Embassy Suites - Fallsview" Sept 26, 2006. Total US$200 / night incl free breakfast & $20 valet parking - a must. Hotel is ideally situated - if you pay for the more expensive rooms on the "falls" side. Definitely worth it. Spend much time sitting by solid wall of windows right over Canadian falls, with US falls beyond. Hotel in all respects is more than adaquate -but not classy. Rooms are from 10th to 42nd floor. spacious, well lit, good beds, linen, etc. Decorator was obviously color blind.
Seeing the sights: "Maid of the Mists" boat trip - a must. "Journey behind the Falls" interesting, OK. We didn't go up viewing tower ("Skylon", I think) - saw plenty from room, boat. Butterfly museum sounded like a real tourist trap but turned out to be fun, very interesting, well done and beautiful. all of these sights are along the Niagara river and serviced by the "People Mover" shuttle bus that runs on the Niagara Parkway.
The consierge at the hotel offers a great package: 5-1/2 hour bus tour including all of above attractions and passing many others - for C$125.00 each (maybe plus tax!). We found (in AAA book) a package for total C$41 each (US$37) the gave above attractions (no Skylon), "People Mover" all day, and the Inclined railway that went right from our hotel on the precipitous cliff down to the Parkway and bus stop. If we'd bought it from home from AAA it would heve been less! Highly recommend this since parking is impossible - nothing on the street, lots are distant and the cheap ones start at C$10.00.
Saw the IMAX - nice but not essential - US$12.50 each with free parking. Don't go for the food: not great & not cheap!
Niagara-on-the-Lake: Charming little town (a la Mendacino or New Hope in the past) half hour pretty ride down the river at Lake Ontario. Fun shops, pretty -not a must.
No customs hassle or delay coming or going. We carried passports - a must after 1/1/07. Never changed money - used VISA everywhere - including parking meters! US$ accepted everywhere.
In spite of "Tourist trap" atmosphere, definitely worth a visit. With stamina you can do the basics in one full day, liesurely in two.
Picture below was taken from our room. At lower right edge is Niagara Parkway (bus route).beyond it is a strip ark that runs for miles along river at level with top of falls. From falls for many miles (to left) the river has cuta deep canyon.
Funicular goes from hotel level (per street seen at lower left) to Parkway. Far falls are the US falls with US city of Niagara Falls beyond. . Aptly named Rainbow Bridge from US to Canada is off the picture to the left.