For students needing calculators for school, the TI-84 is highly recommended for high school due to its reliability and compatibility with lab sensors for data logging. For college, particularly in engineering, the TI-89 is favored for its advanced capabilities, including graphing 3D vector fields, although it may be restricted in some introductory courses. The TI-83 Plus is also a solid choice for both high school and college, as it can handle most academic needs. While some users have experience with Casio calculators, they express concerns about their reliability compared to Texas Instruments models. Additionally, while graphing calculators are useful, many calculations can be performed more efficiently using software like MATLAB or Excel, especially in higher education settings. Overall, TI calculators are seen as the most effective tools for students at various educational levels.