The importance of a navy blazer or sportcoat in any man’s wardrobe cannot be stressed enough, and Men’s Ex recently published an issue focusing on their use in both formal and casual looks. Related posts with more visual guides:
The Versatility of the Navy Sportcoat
Pairing Colored Pants for Spring – Part 1

From Men’s Ex, April 2010:

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Double breasted navy blazers are also classics, but they’re more difficult to do well.
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