The Grand Hotel on Mackinac Island in Lake Huron, between Michigan’s upper and lower peninsulas is quite lovely.
I don’t know if the hotel is fancy enough, but the lake and surrounding area is beautiful, and the hotel is very quaint.
The Blacksmith Inn is run by folks I know. It is very nice, but is right in town and on a fairly large 
lake (Lake Michigan). The lake side of Door County tends to be a bit quieter than on the bay side, but can be crowded. You are not far from nature though.
More remote places on the Lake include Gordon Lodge: https://gordonlodge.com/ and Glidden Lodge: https://www.gliddenlodge.com/
There are plenty of airbnb/vrbo/rental lakeside cabins, but that stretches the “hotel” aspect. Though what you give up gets you unique amenities. How many hotels come with a fire tower?
(OK, that is too rustic for your criteria, but I had to mention it)
There are other similar properties, some are not so rustic.
Brian
Seconded, historic and beautiful. While not on a lake, it’s on an island that is on a lake. We even randomly got upgraded to “the Governor’s Suite” last visit:
We also recently stayed at the Prince of Wales hotel in Waterton, Alberta (just north of Glacier National Park in Montana). Stunning views, and, again, very historic:
Yea, the Grand immediately came to mind.
Very upscale, along with a very upscale price. 
Exactly the place that came to mind. I’ve never stayed there but have stayed a bit further up on the lake; peace, quiet, & only one house in view. Of course it’s busier on the water on summer weekends but a shoulder season weekday is desolate.
I’m sure there’s something in the other Finger Lakes, too. I’m sure there are pockets of buildup; I know there are at the bottom of Seneca Lake (Watkins Glen) & Lake George (Lake George) but they are otherwise mostly barren of commercial activity further up, mainly a few private residences or a nice bed & breakfast, I just don’t know if there are any grand resorts along them because that’s not the type of place I’m interested in visiting or staying at.
* Easily ⅔ of my hotel nights I’m up & out well before sunrise.
There are a couple nice looking properties in Watkins Glen although they are technically across the street from the lake. But if I were to stay there, then the proximity to the Glen itself would make up for any lack of lake closeness.
Canandaigua and Geneva both have lakeside hotels, and the lake views to me from there are only good rather than excellent. But they are both next to lakeside parks, which at first glance only look pretty good as well, but the good soil in the northern part of the Finger Lakes region makes them look naturally lush. (I think Google Street View must have started emphasizing the greenness of the trees in the past year or so, because Kershaw Park in Canandaigua doesn’t look that green, but the second link is a good representation of Lakefront Park in Geneva.)
Can I put in a vote for this one? Granted, I’m biased since it’s the only national park in our state. But it’s really quite special…
The lodge sits right on the rim, and is the only (legal) lodging in view of the lake:
The lodge itself is quite old (CCC era) and rustic, so don’t expect modern amenities in the rooms. But it has a beautiful lobby, a deck with ample seating that overlooks the lake, a good bar and restaurant, fireside ranger talks, and great hikes short and long. Amazing place to cozy up with a book for a few days.
This is what you wake up to, just outside the window:
(though the messy-haired lady is only sometimes there)
And during the day, it’s also quite magnificent from the various lookout points all around the rim:
Crater Lake itself is the deepest lake in the U.S., and one of the clearest in the world. It’s the remains of a caldera formed from an older eruption, with an island in the middle formed from a later one.
The one downside is that the trail down to the lakeshore just closed a few weeks ago, and will be shuttered for several years while they do trail maintenance. It is the only access route down to the lakeshore, which also means you cannot take a boat to the middle island (Wizard Island) until access is restored. The lake is still quite gorgeous from the rim, though, and well worth a visit or three.
IMHO it’s one of the most underrated national parks, and thankfully also one of the less crowded, seeing some 500k visitors a year (vs the 4 million/yr of the more popular parks, or the 12 million of Great Smoky Mountains).
Strongly recommended.
Oh, and if you end up near Bend, Oregon afterward (we’re 1.5 hours from the park), give a holler and I’d love to show you around some other nearby natural sites.
There is a place right on the beach about two miles south of the state line at the base of Ski Run Blvd. It used to be called Tahoe Beach and Ski, but I’m sure it’s changed names a dozen times since. Harrah’s and Harvey’s are actually a pretty short walk from the lake, maybe 1000 yards. There are a few dumpy little motels just to the south of the state line also, but I wouldn’t call them ‘Nice’. They aren’t bad, but straight outta the 50’s.
The place at the base of Ski Run is pretty damn swanky.
Zephyr Cove Lodge is right on the beach also. Historic. Driven past it 10,000 times, but never really been to it, know what I mean? No idea how hard it would be to get a room there.
But Tahoe is a Marvel.
I don’t honestly think it’s nearly at the level of the lake hotels mentioned upthread, but I have fond memories of staying one weekend at Inn of the Mountain Gods near Ruidoso, NM. It’s a casino/hotel in the mountains, so if you’re altitude shy, stay away. Pricewise, it’s probably vaguely reasonable, though it varies depending on the time of year, and if you want a mountain or lake view.
Mostly an honorable mention, but who knows what will tickle our honored OP.
This was my immediate thought on reading the thread title. I haven’t stayed there, but I’ve had lunch at the hotel and walked around the lake. It’s stunning. And there’s nice hiking from it.
I haven’t stayed at the hotel, but the Prince Hotel Hakone on Lake Ashinoko is supposed to be really good. Hakone is right by Mt. Fuji and the view of Fuji across the lake is fantastic.
There was a bad fire in Ruidoso this summer, although the resort sees to have been spared. Might want to check before booking.
Thanks for that! I haven’t lived in New Mexico for, darn, nearly 30 years now, though I visit semi-frequently. I still remember paddling a canoe in the lake at the resort, and heading into Ruidoso to visit their very small bookstore because (pre-kindle) I’d run out of books. 
Not that Colorado is lacking in beautiful mountain towns!
Your question is so general that it’s hard to give a meaningful specific response. But what I’ll say is that most of my experience is in the beautiful areas of northern Ontario. If you Google something like “Ontario lakeside resorts” you’ll find hundreds of them, with descriptions and ratings. It may not be as spectacular as Lake Louise in the Rockies, but it’s called “God’s country” for good reason.
Another option that I’ve used quite often is renting a lakeside cottage in somewhere like the Muskoka area in northern Ontario. There are agencies that specialize in cottage rentals, and many cottage owners are happy to give up their cottages for a few weeks in the summer to help support cottage expenses. All of the ones I’ve rented have been beautiful places and right on the lakeside. Many of them allow dogs and may have amenities like firepits for nightly campfires, stuff that you can’t do in a hotel.