Depends on your price range. However, if you want a moderately (to even cheap) priced hotel with a prime location and great pools, I'd go with the Flamingo. Yeah, yeah, it's not the fanciest. But, really, you cannot beat the mid-strip location or the price. Just make sure you use the hotel website and upgrade to one of the fancier rooms. The upgrade is worth it.
If you want to spend some more money and be a few steps off the hustle and bustle of the strip, I'd recommend Aria. Very modern, clean lines and beautiful views.
Looking for the true, garish, Las Vegas scene? Then you might want to look into the Wynn or Bellagio (both more expensive but all Vegas).