If you fly into Reno, shuttles or cars are the only way to get to Lake Tahoe, 1 hr away. Renting a car will allow you to do some spectacular drives and see this alpine lake.
All the main rental car agencies are available at the airport as well:
Car Rental Reno Airport - comprehensive list of all car rental companies in Reno.
There is a shuttle that runs directly from the airport to South Lake Tahoe as well, if you prefer not to rent a car: