Well, it depends on what you term as best, Indigo scores on quite a lot of points but equally Jet has a few brownie points here and there. Indigo has a better on-time performance, has bigger aircraft on all routes, however now they have also ordered for ATR’s so they will also have routes with these crafts, they have better connectivity and more flights and hence are cheaper at most times. Service both score the same since all airlines in India behave like they are the low-cost airlines and hence can treat customers shabbily and also abuse customers. Jet scores majorly on its frequent flyer program and flashes of customer relationship programs, Their Jet privilege program gives you a lot of special fare tickets and also you are treated better once you cross that level. Inigo has no such benefit
The crew to passenger ratio of Jet is also better and that is one more place they score higher. Otherwise, both are very similar.