Birch wood is generally considered the best among ash, pine, and birch due to its combination of strength, workability, and aesthetic appeal. While ash is known for its exceptional strength and pine for its affordability, birch offers a balance of these qualities with a smoother finish and a more consistent grain pattern.

Birch wood is renowned for its high strength-to-weight ratio, making it suitable for a wide range of applications, from furniture to construction. According to the American Hardwood Export Council, birch has a Janka hardness rating of 1,260 lbf (pounds-force), which is higher than pine (470 lbf) and ash (1,290 lbf). This indicates that birch is less prone to denting and wear, making it a durable choice for high-traffic areas. Additionally, birch is easy to work with, which allows for intricate designs and finishes.

In terms of aesthetics, birch wood has a fine, even grain and a light, warm color that can be stained to match various design preferences. This versatility makes it a popular choice for both traditional and modern furniture designs. Furthermore, birch is less likely to warp or split than pine, which can be a significant advantage in humid environments.

Ash, while stronger than birch, can be more challenging to work with due to its hardness and tendency to split. Pine, on the other hand, is the most affordable option but is also the least durable and has a less refined appearance. Its softwood nature makes it susceptible to dents and scratches, and its grain can be more pronounced, which may not be ideal for certain finishes.

In conclusion, birch wood stands out as the superior choice among ash, pine, and birch due to its strength, workability, and aesthetic appeal. Its combination of properties makes it a versatile and durable option for a wide range of applications.