Modern BG Infect by Sam Dams
Last time I remember playing Infect in Modern, I was playing three colors (green, blue and black) to get the value from Noble Hierarch and additional infect creatures from black. With Ignoble Hierarch giving you black mana now, while also granting exalted to your attackers, you can now easily choose playing just one of them.
This version from Sam Dams is using Thoughtseize and Fatal Push to clear the way for your poison creatures and Plague Stinger and Phyrexian Crusader for additional attackers. Crusader in particular can be almost unstoppable for certain decks like Jeskai Control.
Some of the new pump spells like Scale Up also make the deck better and give you more consistent turn three kills. Wild Shape giving your creature hexproof or making them base 3/3 with trample is also an excellent two-for-one.
If I was playing a Modern tournament right now, Infect would definitely be very high on my list of decks to try to break the format with.