M7, if you’re looking for a large room/suite and a spa, and don’t really care about a show, definitely take a look at the Palazzo, it’s one of my favorites. The Canyon Ranch Spa is nice, $$$$$, but nice ( I believe they offer a room/spa package) and Table 10 is one of my favorite restaurants. Oh and something else that might appeal to you, the Palazzo is connected to the Venetian by a looong walkway lined with shops, waterway/canals, it’s great people watching place.
As far as the Monte Carlo, it’s a beautiful hotel, but I’ve only walked through - maybe D2 has a review