B C Z
I just did a quick agenda count because I was going to build over 49, and I noticed it's impossible because you would need 22 agenda points and Haas only allows for 21 max. Bummer.
Using an unlimited number of Core Sets, the only Corp that can exceed 49 cards is NBN.
After the first datapack comes out, that will change, since every corp will get a new Agenda they can include up to 3 of (for a larger deck) or can swap out with something else for a different Agenda mix.