They sold those "west wing" rooms as an upgrade from the main tower for a while.. I got upgraded to one once (it was only a one night stay) I had been up for almost 48 hrs or I would have walked back to checkin and requested a normal room. Those rooms were dumps! And the bathroom was not even separated from the rest of the room

 

As a relative newcomer to Vegas (5 trips since 2012) I can't say that I've got a favourite- yet. I really enjoyed Hotel 32 but not so much the Mknte Carlo. My first trip was NYNY and I went back there for sentimental reasons but even in a much better room it didn't have the same appeal. The list is below but I'm really looking forward to staying at The Linq later this year.

NYNY x2
Golden Nugget
Hotel 32 (at Monte Carlo)
Planet Hollywood
Ballys

 

My first few trips were in timeshares but once I had a chance to stay in the casinos I could never go back. I think this is the full list. Aria has now become my #1 choice.

The Hilton
Hilton Grand Vacations Club
Grandview
Imperial Palace
Wynn x2
Monte Carlo
MGM Grand
Encore
Bellagio
Aria x4

 

First hotel we stayed at in 1990 was Excalibur.

 

I've stayed all over the Strip.
Mirage
Caesars
Bellagio
Monte Carlo
Excalibur
Mandalay Bay
Planet Hollywood
Paris
Ballys
Flamingo
Imperial Palace
TI

My favorite would be PH. It certainly isn't the nicest on the Strip, but it feels like home. I love the dealers and floor people at PH.

 

When I was young, my parents brought us to meet up with Grandma and Grandpa who were flying in and staying at the Lady Luck. My parents had booked us a campsite with our pop-up trailer at the KOA. In August. That lasted one night, then we got a room at Sam's Town.

Since 2010, have been at a number of bachelor parties between Wynn and Venetian/Palazzo. Stayed at Gold Coast and Monte Carlo for a conference recently.

 

DI, Riv, Trop, Caesars, Stardust, Sahara, Hacienda, Sands, Mirage, GN, Bellagio, Aria, MB and MGM. Aria was the nicest that I've stayed at. My best memories are from the Stardust when I was in my 20s along with the DI.

 

I have been staying since 1976 first at Westward Ho. I have stayed at some many times
W HO
Thunderbird
Dunes
MGM( 2 weeks before the fire)
Holiday Casino(before it was Harrahs)
Frontier
The motel by the Welcome LV sign(with Pink Elephant out front)
Sands
Mirage
Excalibur
Luxor
Mandalay Bay
Harrahs
Caesars
Flamingo
Paris
Ballys
Venetian and Palazzo
Wynn
Planet Hollywood
Aria
Cosmo
Golden Nugget
I think my favorites are V/P and Wynn with edge going to the V/P because I get offers from them. The Cosmo, where we stayed over SB was very nice.
I also really enjoy the Golden Nugget because I get much better comps for my level of play.

 

I'm really really miss DI.

 

Wow..ok, here goes (but my memory may be a bit impaired, so I may have missed some):
83 trips... number of stays in (parantheses)
Castaways (1)
Mirage (3)
Dunes (1)
Old MGM (Bally's now) (1)
Westward Ho (2)
Flamingo (3)
Harrah's (3)
El Morroco (1)
Riviera (2)
Las Vegas Hilton (5)
Imperial Palace (3)
Rio (1)
Gold Coast (2)
Caesar's (1)
Golden Gate (5)
Golden Nugget (2)
4 Queens (4)
Fremont (6)
'theD' (1)
Plaza (3)
Stardust (35+)

Just guessing at the Stardust with 35 (or more) stays, but it sounds about right... and that is the answer to the OP's question... the Stardust was clearly my favorite... certainly not the "nicest" in terms of luxury or amenities (that would be a suite-stay, twice, at the Mirage), but it was certainly the property I enjoyed more than any other... they took great care of me & I loved the casino there.
The total stays is over 83 because I had a few trips with two different hotel stays.
If I left any out of my list, it would most likely be Sands, Aladdin & Frontier... I may have also stayed at the Silver Slipper once, but the early 80s are still hazy regarding some of those trips, so I'm not sure. I know I used to gamble there a lot, so it genuinely possible.