As far as I know, TI-83+ is still the standard. The higher levels of TI's have more features, but are often banned on things like the SAT. They're also a lot harder to use. On the other hand, your teacher and most of your fellow students will probably be using 83+s, so they'll be able to help you figure out how to do things.

Since you mentioned the TI-89, I just checked: It's the highest level of TI allowed on the SAT, but it is BANNED for the ACT.

Yes, many things such as Mathletes and the ACT do not allow you to use TI-89 or higher.

It really depends, though.

If you have already done all that stuff (ACT all that other stuff that might bar TI-89's), it might be a good idea to geta TI-89. Especially if you will continue on into higher levels of Calculus. If you still have that stuff to do (maybe even an AP Exam), I suggest getting a TI-84 Plus Silver Edition. It is basically a TI-83 with a few extra features (and it is allowed on all of those things).

Thanks for the recommendations.

I picked up a TI-89 Titanium yesterday. I'm happy with it so far. I probably should've mentioned that I'm minoring in mathematics so I'll be taking a few post calc classes like linear algebra. I think it's probably the best fit for me, and I've already taken the SAT so that won't be a problem.

Thanks again for the help.

As a math major...you rarely use calculators in college.

I have my Ti-83 on my desk, and I've used it maybe 4 times in the 4 years I've been here, and probably 3 of those were on things not related to my mat classes.

TI-83's are fine for most people. TI-89 is good for calculus and other stuff. It can do things (such as calculus) that the 83 cannot. I have both and really love the 89. It is a good investment, in my opinion, if you're doing calc.