... In Vegas these days?  I noticed a lot of older hotels are offering rooms for under twenty bucks a night.  And not just really old like Tropicana, but even Luxor, NY and TI.  Even good sized suites are less than 200.

Is there just no business?  What are the best areas to stay these days?  Like without a lot of construction and some decent social life going on.  I would like to host a dinner date so it would be nice if there's some social life nearby and not just a bunch of closed restaurants.

Seasonality plays a significant role in why the same hotel room can cost one price one week and a higher or lower price the following week or month. When a location is in its off-season, hotel rates are less expensive. July and August are typically off-season months in Las Vegas due to people spending more time with families, staying away from Vegas due to the heat, fewer conventions in town, etc.  

You will not find a correlation between lower hotel rates and restaurant closures. Come to Las Vegas, reserve a discounted suite, contact a classy provider, and enjoy dinner with her at one of the many elegant Las Vegas restaurants.

I would go with any of the following  
Wynn
Encore  
Aria
Cosmo
Venetian  
Plazzao  
Maybe Mandalay  
Mgm grand

I adore dinner dates

Xo
LaRue

I get it, The Bellagio really has no or shitty restaurants...I stay there but I never eat there,

Several years ago I became a “Red Card” member at Wynn/Encore. When you play games, you gain points on your card, which may entitle you to a free night or two. BUT, the part I like about the membership is that you receive emails showing seasonal discounted rates. I’ll locate the discounted days on the calendar and telephone the hotel. The hotel usually gives me an even better rate than the Red Card rate. The lower rates seem to correlate to no or less conventions in town or a slow week.