What dates are you planning on going? These are important as some dates tend to be more expensive than others. Sometimes there are big events or concerts in town. For example: The Country Music Awards or IHeartRadio Music Festival. These draw large crowds.
Are you planning on going during a weekend? If so, expect hotels to be more expensive. If you can go during the week, rates are always much cheaper and you can find some great deals.
I would keep away from Luxor and Excalibur. I've read some bad reviews lately. I've seem some pretty decent rates lately for NY NY and MGM Grand. Monte Carlo and Mandalay Bay are pretty nice as well. Not the best, but certainly not a dump. Most people find the downside to Mandalay Bay is that it's on the end of the strip. Love the pool here.
Flamingo recently renovated a good portion of the rooms at their hotel. That might be worth looking at as well. Paris and Planet Hollywood offer some good rates. I've always enjoyed Mirage as well.
Sign up for the Players club cards and email alerts. There are times they will offer you great rates on the rooms.
M LIFE is one card for the following hotels/casinos: Mandalay Bay, Luxor, Excalibur, NY NY, Monte Carlo, Aria, Bellagio, Mirage, Circus Circus and MGM Grand.
Total Rewards is for: Caesar's Palace, Harrah's, Flamingo, Bally's, The Quad, Paris, Planet Hollywood and Rio (off strip).
Hope this helps.