Believe S/X are still the Flagships.
S is the most beautiful, has the longest range, is the quickest and highest speed. It has much greater interior volume than the 3, is made of high tech aluminum underneath, has the largest wheels and brakes, has the premium adaptable and adjustable air ride suspension, has two displays instead of just one in the middle, has the most rear seat passenger room, etc.
The X has the signature Falcon Wing doors, is equipped to tow 5,000s, seats up to 7, has an option for executive rear seating, has the most carrying capacity, qualifies for Section 179 tax breaks for profitable business owners, has the fantastic panoramic windshield, the latest ceramic bearings, and the best of both worlds front and rear motors.
Both S&X can come with Ludicrous Mode, and are in line to also receive the ultra high performance 3 motor Plaid Modes. They also have the fresh air HEPA filters with Bio-Defence mode and come standard with private gate/garage door actuators.
Model 3 is cute and nimble, and comes with some newer gadgets, but a big stretch to call them the Flagship of Tesla....plus they are much more common. More that they are the value brand. Don't even come with self opening power doors or hatch. Even a simple fob costs extra.