We have seen quite some criticism about MEMRI on DF. As I am taught from a very early age on to formulate my own ideas and opinion, and indeed was encouraged for independent thought process, I will not quote other opinions, but just write my own. The OP will end with a challenge.
The main criticism against MEMRI (and PMW) is that it misrepresents Arab media and that it mistranslates.
First, misrepresentation. It is true that in the Arab media there is not a constant flow of hate speech against jews and the west. On the other hand, there is frequent hate speech, that gets almost no negative attention at all from Arabs themselves. Some time ago a Kuwaiti newspaper had a moment of clarity, and applauded MEMRI for what it did, for the same reason as event horizon posted: show me an Arab variant of MEMRI that highlights hate speech!
Second, mistranslation. This is what the challange is about. For the native Arabic speakers on DFto find one vid from MEMRI or PMW that is mistranslation. This applies to vids posted on DF, or indeed on the MEMRI and/or PMW website.