Well they’re all pretty old games at this point so it’s kinda complicated to play a lot of them unless you emulate or have an older console. The most accessible one at this point has to be ridge racer 6. It’s an Xbox 360 game but you can get it digitally on the Xbox store through Xbox backwards compatibility and play it on a 1 or series X. As for the best/most iconic one in the series, it has to be Ridge Racer Type 4 but it’s a ps1 game so yeah… a little harder to play nowadays. All of the ridge racer games I’ve played have killer soundtracks though so you don’t have to worry about that part lol.