I currently have a TI-84+SE that's showing its age. Is that still one of the best choices? Should I just hunt down another TI-84+SE in good condition?

Or should I upgrade to something like a TI-89? Or even go more modern? Is it even worth hunting down these older models with black and white screens, or are new ones really much better?

I've looked around and I'm not entirely convinced by these new calculators that have color screens and backlights, the batteries must really not last that long.

Indeed, if you compare the battery life of your ti-84 plus SE to a ti-84 plus CE, there is a noticeable difference, but I would not say the CE's battery life is bad, you just have to plug it in every now and then, its not like a smartphone that you would plug in every night or anything. As a person who owns both new and older models, I would personally recommend opting for a new color model (DON'T BUY the CSE though, ITS GARBAGE). It really depends what you want to do with it though, if you will be using it to code and to use everyday, then I would go for a CE, however, depending on your needs, you may need a calculator equipped with a CAS (notably for a calculus class, or any application that would require you to do things like simplify equations, use infinity in your equations, compute indefinite integrals, etc.) Here is an example of a recent situation where the difference between the two systems was brought up. The ti-89 which you mentioned, is essentially a ti-84 with a CAS and a fancy GUI, its definitely a good calculator.

The CE.

The calculator's battery life (for me, and I use it every day) is like 4 weeks. It's crazy. (Although I do have the brightness turned down, all the way. The highest brightness (a) kills the battery and (b) kills my eyes.)

The CE is also pretty fast, but my other calculator is an 85, and is terribly inconvenent.

I don't have this problem because I have rechargeable batteries. Although it does bother me that i have to change the battery every time and risk losing all my data. (because I can't guarantee if the coin cell is full or not)

Well, it depends on your needs. I'm assuming you are in high school/college, so you might want to see this.

In my opinion, the CE is the best choice. It has long battery life and is now very commonly used for many things (TI-Innovator Hub, E3, etc) and is easily programmable with faster speed. Teacher's might not want you using any CAS calculators because it's too "fancy" (which means to not just jump into buying an Nspire) and like mr womp womp said, don't get a CSE, especially when you can get a CE for about the same price. Buying something like an 85, 86, 89, V200, or any other calculator that doesn't support TI-Basic isn't a good choice because teachers might teach you a bit of Basic every now and then for classroom use, and the mentioned calculators don't support Basic.

Hope this helps!


EDIT: Pay no attention to this post. See mr womp womp's post below instead

Dear Battlesquid,
The following models: 85, 86, 89 and V200 all support a version of ti-basic, albeit not the same as the ti-84s basic. If you have an 85,86,89 and the teacher goes through how to build a quadratic solver, you should be able to figure it out I'm not very familiar with the V200, but it definitely has a form of ti-basic available.
Here is some ti-86 basic code that solves the quadratic equation...

Code:

As you may have noticed, its the same as a ti-84 basic program to do the same thing Of course, ti-86 basic is not the same as ti-84 basic, but it is quite similar. This exact code could be exported in both .86p and .8xp and would work fine on its respective calculator. It will also work on the ti-83 models, ti-85 (.85P) and ti-82 (.82p) as well.
Just for fun, here is the same code with slight modifications which would allow it to run on a ti-84 but not on a ti-86:

Code:
In ti-86 basic, you must close your quotes.

I leave mine on the highest brightness, and use it for about an hour a day in math and homework. The battery lasts three weeks or more with consistent use like this for me.

I also think that the CE is fast, but not as significantly faster compared to an 84+SE as you might expect. Maybe a 50% speed increase in graphing functions, for example.

I love programming on the CE, as it uses standard TI-BASIC language, asm, and can now be programmed in C. I also recommend trying out ICE, an axe-like on-calc code compiler for the CE, although its syntax is incredibly similar to TI-BASIC.
You will appreciate the 10 rows in the BASIC programming IDE as opposed to older calculators 8 (I don't know how this compares ti an 89, I dont own one).

Agreed. I use mine more extensively, so that explains the time difference.

The CE can also run TI-Basic programs (they may not look the same, though) for the 83, 83+, 84, 84+, 84+SE, 83+SE, 84 CSE. They have to be pure basic, though. (I believe)

I love programming for Casio Prizm i.e. Casio FX-CG 10/20 when i have some free time - you can program add-ins in C and they will appear in the main menu just like built in apps. It has large screan and memory plus serial interface and long battery life.

I really like the 68K calcs... TI-89, 92+, and V200.

I love the Motorola 68K processor; 16/32 bit, big endian, 256KB RAM, and lotsa Flash. And back in the day it had the highest lcd screen resolution.

But... it is showing age. The new color calcs are stealing the show. I may jump to a color calc soon.

I would go with a calculator that has color and (relatively) high resolution. Programs involving graphics are noticeably more pleasing to the eyes if on a color and high res screen. However, as a CSE owner, I would say go with the CE. The CSE is basically a SE with more complications than improvements. I wish I waited just a bit longer...

Yeah. Sense the graphics libraries for basic programs are not completely released yet, none of the programs written that require Doors or xLIB work,and the CE uses the ez80 processor which means none of the earlier ASM programs work either.

BUT, the CE has ICE which is arguable much better than hybrid libraries.

Some asm programs will work, some won't. As for the libs, Doors is not yet released, but it is pretty much complete, and the programs do work for the most part.

I'm still a big fan of my TI-84+SE but if it broke and I had to get a new one today, I'd get a TI-84+CE for sure.