The companies are both doing well in the growing rideshare markets.Lyft (LYFT -0.09%) or Uber (UBER -0.02%)? That's the question millions of rideshare customers ask every weekend. They should also be asking is which stock is best for their portfolios.Historically, Uber has outpaced Lyft, with its stock generating a total return of 137% since going public compared to a 56% loss for Lyft. As the larger player with its hands in more sectors (such as food delivery), Uber has reigned supreme with its $200 billio ...