It's pretty interesting to me how all the Americans think a 5'9" guy should weigh close to 200 pounds, while the Euros think he only needs to gain about 15-20 pounds. It's a reflection of each others' cultures.
My roomate is about 5'8" (for the purposes of discussion that's the same as 5'9") and is about 205 pounds. HE LOOKS LIKE A PIECE OF SHYT, physique wise. His ideal weight is about 175-180 (he's an 'endo-mesomorph' - stocky and wide, but prone to fatness if not careful), but he's in denial and says that that is his ideal weight. It's funny, because I am actually STRONGER than him (can press/lift more weight) at 5'9" and 165, am more agile, and can jump higher/explode faster, and have faster reflexes. Furthermore (and perhaps worst of all), he can't find any stylish 'metro/fashion' clothes that fit him, so he wear baggy-ass garbage bags from stores like Wal-Mart.
....
bottom line, you don't need to be that guy. Don't be the loser meat head with no neck that the girls run away from.
There are ways of creating the illusion of dense muscularity, and this is especially true if you are thin and fine-boned. Just concentrate on these specific body parts:
Shouders
Triceps (biceps to a lesser extent)
Abs (pay attention to your CARDIO and obliques!)
Chest
BACK BACK BACK (LATS LATS LATS) !!!!!
The trick is to gain that coveted 'V-Taper' - annihilate your waistline and whittle it down to about 30-31 inches (what's your waist size, Jay-X?), then blast your lats until you can't breathe. Keep the intensity up on your chest and tris (which you can conveniently work on the same day at the gym), and soon combined with your small bone structure, you will create a physique that will give you the illusion of a lean, MUSCULAR, and powerful body. Think about the model Marcus Schenkenberg - he has a bod that girls DREAM ABOUT IN THEIR SLEEP. He's like 6'3" and 185 pounds - but he's probably stronger than most guys who are his height and weight 210 pounds. There is no need to look like 'The Rock' - you'll just look like a circus animal. The buzzwords are
LEAN, SMALL-WAISTED, and WIDE BACK. I hope that helped.