Sorry to sound like a broken record, but PGR4: perhaps the perfect arcade racer? I know this is a controversial statement, and that many of you will fire back with, "What about Burnout: Paradise?" Well, for gameplay, B:P about ties with PGR4. But I think it's advantage PGR because of licensed cars and bikes, interiors, weather and its very-well-realized city tracks.
Anyhoo, PGR4 is perfect because it's an arcade title that you can play as a sim (or in a way approximating a sim). If you want to, you can barrel down the Manhattan bridge in an FXX, exceeding 200 miles-per-hour by the end, then slam on the brakes at the last instant to avoid plowing into the HSBC Bank as you turn onto Bowery.
Or, you can take a Maserati 250F around Nurburgring Winter Sunset. Not only do you get to enjoy the scenery, but you get to pilot an unwieldy car on a finicky old suspension around a snow-slick track. This means dialing-in braking points, turning in at just the right moment and nailing an apex. This is not only a rewarding racing manoeuvre, but one that earns you a GREAT TURN Kudos.
I guess in the end, this boils down to choice. Do I want to zip around Tokyo in an Ariel Atom or should I manhandle a Norton Manx along the Thames? Could I slide a RUF CTR Yellowbird the entire length of the Las Vegas Boulevard Tour or enter the Matrix riding a Xerox Ducati 999 on the Nevskiy Run? That's only scratching the surface.
PGR4 is fun, it's serious, it's accesible, it rewards your skill, it indulges your fantasies and does so with beauty and detail. I think PGR4 might be the perfect arcade racer.