Really depends on what you are looking for. In terms of straight projections, MLEs (Minor League Equivalencies) and draft strategies, The Forecaster is the choice. The thing I find most useful about the Bill James Handbook is his Ballpark Index section. It shows how each ballpark played in the previous season, as well as over the last three years. That alone has proven reason enough for me to buy it yearly. I'll be open right up front, I write for The Hardball Times, so take this with a grain of salt if you wish, but Brian Cartwright's OLIVER projections are pretty awesome. They are part of THT's Forecasts. The Forecasts aren't free, it costs $14.95, but you are privy to updated in season projections all year. The forecaster includes projections for the next 6 years, as well as MLEs for minor league performance, and equivalencies for performances in foreign leagues such as that of Yu Darvish and the other NPB imports and expected Cuban signings. I won't link there, because that feels spam-ish to me. Overall, you can never have too much info.