All of these should be fairly competitive:
Manchester City v Barcelona (Would not be shocked if City took this one)
Olympiakos v Manchester United (Toss-Up)
AC Milan v Atletico Madrid (The only sure bet, Atletico)
Bayer Leverkusen v Paris St-Germain (PSG)
Galatasaray v Chelsea (Slight leaning to Chelsea)
Schalke v Real Madrid (Real Madrid)
Zenit St Petersburg v Borussia Dortmund (Dortmund)
Arsenal v Bayern Munich (Bayern, but it won’t be a cakewalk)
Arsenal gets Bayern two years running. Lucky them.
Having the away leg first will be big. City’s success depends on which of their teams shows up. On their day, Barca and Bayern are the best club teams in the world.
Right now I like all the higher seeds with the possible exception of United due to RVP being injured and my disdain for David Moyes. I can easily see him playing one striker in the home leg.