depends on location but seeing you're in the vicinity of me (MN) Id have to honstly say 3
Unless you need like PAS9 (58W) I would do something like this. KU is on the following
105,107.3,111.1,121 are subscription services so unless you have those, they really don't count. 99 & 127 doesn't have anything on it either. Another issue is from 103 to 123 there is only 2 satellites that have stuff on them so there is kinda a wasteland
So one dish could do 72,74,79,83,85,89,93,97,101,113 and the other could do 87,91,95,99,103,116.8,123,129. That would cover all the active satellites.
I use one with 72,74,79,83,85,91,93,97,101,103,107.3,110,119. 107.3, 110 & 119 are for subscriptuion services. 2nd 36" dish for 123 & 129. SO I'm missing 87 (which I am working on wedging it in between 85 & 91), 89 (not much on there but ABCNewsNow), 95 (CCTV). 113 & 116.8 are useless to me as I know speak Chinese or Spanish