What games do you like to play? If you are a 21 player, the rules in Northern Nevada vary quite a bit. If you are just looking for a decent casino with at least some smoke control, halfway decent rules, and reasonable size, I would recommend the Silver Legacy, Peppermill, Atlantis, Grand Sierra, and John Ascuaga's Nugget, all in the Reno area. The choices are very limited in Tahoe - in Stateline, there are only a handful left, and only Harvey's and Harrah's are worth mentioning.
But if you like dives, amputees, drunks, silver dollar ploppees, and people without any decorum, Reno is the place to be.