For me it's Raiders and then TOD
TLC is average at best.. I never cared for the Humor used in that one.. Too many goofy characters being Goofy. Sean Connery and the Tank Chase saved that film. Worst villains of the original 3 IMO. I thought Fords acting was a bit phoned in also.
TOD has it's fair share of goofiness but it works better IMO. The Chemistry between Short Round and Indy is great and Willy is just an homage to Fay Wray. Plus I think Indy's reactions too her are appropriate and work. It's not a perfect film but as a sequel to one of the greatest action films of all time it did a great job and took some chances at being a completely different type film.
KOTCS is awful as a whole... But I find the first 40 min enjoyable enough.. Nothing great but enjoyable... Then Marion shows up and it really goes down hill from there... I am not putting it all on her It's just the film really took an awful nose dive. Goofy stuff happening left and right. No sense of danger for the audience or the characters on screen... It was a big TV sit com.
I am OK with a new Indy if they can do it right... If not then I still have the first two and parts of the third.