HAVE FUN .... it's impossible not to!
SixKiller is correct ---- Monte Carlo's got a nice brewpub ..... if you like good beer, you'll enjoy yourself there
I don't know what type of gambler you are, but I'll be the first to tell you that I'm not going out to the craps tables to blow $2,000 --- I'd prefer to place my $$$ on some football games or something I've got a better feel for ---- if you're frugal with your $$$, do yourself a favor and walk around the strip and see as many of the casinos as you can ..... the "cheaper" the casino, the easier it is to get drinks at the snap of a finger ....
since you're staying at RIO, you HAVE TO hit their buffet ....... more food there than you'll ever see in your life! make sure you go to that place HUNGRY
also worth checking out the breakfest buffet at the Flamingo