Hi there,
It is really hit and miss - i would not make a decision based solely on analysts recommendations/estimates. What I tend to look for is company performance versus estimates. Does the company have a strong record of performance, or does it tend to miss expectations on a regular basis. If it regularly misses, then it is likely that the company will continue to disappoint. Same is true on the flip side.
It also depends on the analysts and the industry. The more mature the industry, the easier it is to predict and thus the more likely analysts are to be accurate. Likewise, some have a much better track record than others, so it is useful to understand their history and if their company has a stake in the company which could impact impartiality (although it shouldn't - reality is that it most likely does).
Mat