Test cricket is cricket in its purest form, nothing can ever come close to it. But it depends, some fans are crazy about cricket but they don't like test cricket, in Asia, most people would think that the shorter formats are the real thing, but its rather the media which makes it look like that. Test cricket doesn't get that much attention or coverage, whereas T20s or ODIs are given so much importance that the fans fail to understand the value of test cricket.
ODIs "used to be" competitive and was an important format, but, recently, the new rules have just made it an extended version of T20s. Now every Tom, Dick and Muhammad comes lower in the order and thrashes all the bowlers since there's no reverse swing, no spin and 5 fielders are placed inside the circle. ODIs have become a joke and ICC has really spoilt a wonderful format by trying to make it more entertaining.
T20s can be enjoyed for the individual performances, but then there's nothing else to look at. Just enjoy it if you like it.