Where to go after "Programming in D"

[karabuta via Digitalmars-d-learn]

I am almost done with the "programming in D" book. Where will you 
suggest a go from there. My current focus is on network 
programming, database systems, data manipulation and software 
architectures for database related apps(mostly Linux platforms 
with D).

I am aiming to become a hardcore and better coder(quality code) 
than you :) Please suggest.