man2man

In general, you'll want inside shade/one step ahead on any player in man coverage so they stick to the recievers better and are more likely to be in position to contest the catch. Inside shade is generally preferred over outside shade as most popular formations are tight formations where most players begin their routes inside the numbers. But outside shade would be preferred if you play a lot of people who line receivers up outside the numbers. One st3p ahead is practically inside shade + outside shade. Shutdown x-factor is also something to consider here as it effectively gives you one step ahead and pick artist. 

The other stack to consider is for players with special Universal Coverage x-factor. Having every KO is very powerful, the hope here is that even if your players get burnt, they can still prevent the completion because they have a KO. Standard UC also works well as the x-factor on any player with inside shade as it's never bad to have more KOs.

To sum it up players with free inside shade, TTR with x-factors, Aka players, CB Boldin, FS Chad Johnson, Comp Pass JPJ all meet at least one of the above criteria.

Boldin is the only player with free one step ahead so he can lock almost anyone down regardless of where they lineup. 

A lot of the RP CBs are great for man. Provided they get the discounts, they're some of the only players who can get two 0 ap man abilities. I would suggest pretty much any of them with free inside shade. They are my top picks for man if we're only talking about abilities.

JPJ would be my top pick for a UC guy as his is always on for only 1 ap. But you're out of luck if you don't have him.