Well Casios are better than TI calculators. My current favorite calculator is Casio ES-115 PLUS2 https://www.amazon.com/Casio-fx-115ESPLS2-Advanced-Scientifi... I like it because when you enter sin(pi/12) you get (sqrt(3)-1)/(2*sqrt(2)) in mathematical notation, which is really nice for a $16 calculator. Here I'm going to hurt TI: If you need a TI-84 or TI-89 for school, the place to get them cheap is shopgoodwill.co…
For scientific calculators, I would agree. For graphing calculators they might be better on technical merit or cost, but everyone is going to write programs for the TI so you might as well get that one.