Material or Initiative?
Here is a game from the recent Mediterranean 2013 Open Tournament which illustrates the battle of Material versus Initiative. Here is GM Sedlak - IM Sebenik with full annotations and commentary:
This game was a great example of the battle of initiative/material and the dangers of delaying castling and king safety. Sacrifices like 5. g4, 14. f4, 16. Bxf7+, and 21. Bb6+ show that material is not always the important factor. The fact that black had delayed his development with some questionable moves in the opening and early middlegame allowed white to find these spectacular sacrifices to steal away the initiative and build an attack on the king.