Which 3g internet is best?

i am a heavy downloader so u can tell me which 3g sim i purchase for my 7.2 mbps modem !tell me which 3g sim (relience 3g,idea 3g,tata docomo 3g! E tc)is best in network aswell as speed !please dont tell bsnl 3g bec. I have it n it is all crap!thanks