>>713597560
2 (Arcade)
Rave Racer (Arcade)
RRV (PS2)
RR7 (PS3)

if you are playing on a PS1 is is required to use a NeGcon, otherwise play the arcade versions with Vivanonno and a wheel

the ps1 port of RR is not very good honestly
Rave Racer never got a home port and is very much worth playing
R4 is more of an "multimedia project"
RRV is like R4 in some ways but is a much more fleshed out racing game
RR7 is an improvement of RRPSP/RR6

so of the respective game eras i'd say those are the worthy ones.