"Modern" is a relative term I think. Original Vetiver and Original Santal are a couple of their most recent offerings.
Millesime Imperiale is IMO their most popular sort of "modern" scent. It is in the vein of the lighter scents that came to dominate men's frags so much in the 90s- but with a bit of Creed "punch." Silver Mountain Water close on it's heels.
GIT and BdP from the 80s are kind of modern classics...
I don't think we can pin this one for you. You need to read up on the reviews and other posts. Creed makes a wide, wide range of different scents. Depends on what you like.
Edit: Forgot Acier Aluminum and Himalaya. Two more in the modern vein. And Virgin Island Water.
GIT is the best seller, Bois du Portugal is quite possibly their best. You can't buy this stuff blind. The problem I have with the modern Creed scents is that almost all of them dry down to a common buttery Ambergris note of which I'm not fond. As far as a modern one, probably Millesime Imperial with that champagne opener.