I do hate to rip on places, but I recently stayed at the Monte Carlo in Vegas and I have a few things to say about it.
First, I'll point out that it's cheaper than most places on the strip, there's a McDonald's inside in the food court (great for breakfast and when you don't want to spend $80 on dinner), and the casino is pretty good. Also, the location of the MC, with the help of the tram, is pretty darn good. All of these things make for at least 3 stars.
However, having stayed at a bunch of other hotels on The Strip, this place was the worst from a room comfort perspective. The rooms were built in the 80s or something and they certainly show it. There are cracks and mold in the bathroom tile, the showers aren't great, the carpet is stained, and the fixtures are way out-dated. I guess I'm a bit of a snob, but I couldn't see past all of that. I stayed here for a few nights and then stayed at the Bellagio for a few nights, and the difference in comfort level is pretty staggering - to me.
If you don't care about the details and are on a budget, the MC is probably a good place for you.