Our experience -
The Thayer: we always stayed there when available. You can't beat the convenience, one being that you are on post and don't have to go through security every time you drive on post. Stayed there for R-day and Graduation. For R-day, stress level was high enough and we didn't have the extra worry of traffic and getting to Ike Hall at the assigned time. There was a shuttle from the hotel to Grant Turnaround, but we walked up. Graduation - again we didn't have to worry about the stress of long lines at the gates and getting to graduation on time.
West Point Hotel - Highland Falls: We stayed there twice. First time it was was less than desirable. Second time, it was better. Not fancy but it was clean and had been recently redecorated.
Econo Lodge: It was disgusting. I felt I needed to don a hazmat suit while staying there.
Holiday Inn Express - Ft. Montgomery: We stayed there twice but only during non high volume weekends. For the big weekends, they jack the prices up to about the same as The Thayer.
Hyatt - Fishkill: We stayed there a couple of times and it was very nice. The free breakfast was wonderful. It was called the Siena Hotel when we stayed there before Hyatt bought it out. Drive to WP isn't bad.
Homewood Suites at Stewart Airport - Newburgh: Great place. Stayed there a couple of times. We stayed there for A-Day and it was great to have the suites floor plan. Cadet came back there and crashed and we could be in the other room and not bother him. Plus, with the kitchenette, we could cook some of his favorite foods. Very convenient if you fly into Stewart.
White Plains area: We flew into White Plains many times and stayed in hotels there as the price was much cheaper than those right around WP. We stayed at the Hampton Inn, the Doubletree, and the Renaissance.
Nanuet/Nyack area: We stayed at the Hampton Inn a couple of times in Nanuet. Hotels in this area are usually more reasonably price and have availability on high volume events at WP (A-day, R-day, Graduation and football games). The drive isn't bad and actually a very pretty drive up the Palisades Pkwy
Dolce - Palisades: We stumbled upon this place and it is lovely. It is an IBM Conference center and on weekends the prices are very reasonable. Great place if you don't mind the drive.
** Warning about staying in Newburgh. I would only stay in hotels around the airport. Parts of Newburgh are very sketchy. When DS stated WP in 2009, Newburgh had the highest crime rate in the whole country, although I think it has gotten better since then.
Airports: We flew into either Stewart or White Plains. We flew into NYC once and the drive to WP with tolls and traffic just wasn't worth it to us. Stewart usually pretty pricey but a couple of times, we found some good fares. All other times, White Plains was very competitive with NYC fares, so we flew to White Plains.
Just writing this brought back good memories of good times. Yes, we went a lot to WP during DS's years there, but we made the decision early on that we were going to visit often, even though it would be costly. He was only going to be there 4 years and we wanted to make the most of it. The Hudson River Valley area is beautiful with a lot of things to do. The small towns across the river have good shopping and wonderful restaurants. West Point itself is beautiful with many things to see there (Trophy Point, the cemetery, Cadet Chapel, Michie Stadium, the Plain etc)
If I had to narrow down the events that you should do if you possibly can, they would be: A-day, PPW, Ring Weekend, Graduation and at least one football game.