Best reasonably priced hotel to stay at in Las Vegas?

I'm going to Las Vegas with my boyfriend to celebrate turning 21. I want a fun environment that would be close to attractions on the strip, I want a pool, and I want something not too hard on the wallet. As of now, I've looked up hotels online and the one's that I have it narrowed down to in terms of price, experience, and location include Luxor, Flamingo, MGM, Treasure Island, New York New York, Monte Carlo, Bally's, Harrah's, Planet Hollywood, and Excalibur. So if anyone could help me narrow this down a bit, I'd really appreciate it! Please try to include the good and the bad because, ultimately, my college student budget might have to take high priority in the decision making and I want to make an informed decision if I do have to settle. Thanks!