Manchester City and PSG would be an interesting and great game to watch, Both are top teams and even if Manchester City isn't doing great in there league they are still a team composed of top players, CL is always more tricky than local leagues too.
I think PSG have a bit advantage because Man City don't have good situation , opposite of PSG which has won the french league and they are very enthusiastic to go far in champions league.
PSG vs Man City for quarter final on champion league i do believe PSG will defeat Man City but i don't think they will be champion this season
and i guess the highest achievement for PSG will only goes to semi final