Lyft is a great alternative in between taxis and public transit, but the somewhat egalitarian nature of the service means you don't always know what to expect. Recently Lyft rolled out its Lyft Plus premium service in San Francisco. Lyft Plus still relies on independent drivers, but they've been sold special white Ford Explorers customized by Lyft to meet a higher standard than you'll usually see in normal Lift vehicles.
Lyft Plus Explorers seat up to six passengers in leather seats, making them a pretty good choice if you've got a handful of people that need to go somewhere and you'd rather not cram into someone's Civic. The cars also have audio systems with Spotify Premium playlists. Naturally, these premium rides cost more, double the price of a normal Lyft ride according to sources who've tried it. That puts Lyft Plus well above the cost of a standard taxi, but still below a limousine, and notably, below the premium offerings of competitor Uber.
Not all users have access to Lyft Plus at the moment, according to the info page. Check the Lyft app to see if you're included - if you are, there should be a large "Lyft/Plus" slider at the top of the app after you log in. Right now it looks like Plus is limited to San Francisco, but it should expand further as more Lyft drivers are accepted to buy or finance the new Plus SUVs.