Despite its raw power, much higher than that of the TI-Z80 and the TI-68k series, the Nspire series remains quite a disaster, as far as programmability goes. This is because TI made the Nspire family closed platforms, turning the back to ~15 years of openness of the TI-Z80 & TI-68k series, whose programmability helped make TI the marketplace leader...

If you have the money to throw around, go with either a CX or a prizm.
pros for the CX:
-larger,more active programming community(and we have people like critor working tirelessly to crack them open)
-if you like lua, this calculator's for you
-in terms of gaming, the CX is faster than the prizm, and there are already GBC and NES emulators available
pros for the prism:
-Casio isn't actively locking the prism down more with each update-in fact, they even fix reported bugs(locate glitch, for example)
-the Prism allows native assembly code and C without having to exploit loopholes in the OS like ndless
IIRC, it's better-documented at the moment

From what I recall, the Prizm ranges from $100 to $120 while the CX is something like $140-150.

You can buy both for a bit above 100 dollars. Nspire still enjoys Lua Programming, so it still has some programmability. Casio development is probably a bit more active on Cemetech though...

The TI-83+/TI-84+/TI-84+SE are nice choices as well. You have the options of BASIC, ASM, Axe, Grammer, or any handful of ASM libraries at your disposal for programming. They aren't as fancy as the Nspire or the Prizm, and only offer a B&W display. They are completely open platforms though, have a huge library of games and programs available for them, and many active coders.

Oh, well carry on then.

If you can, get a TI-89 Titanium. Otherwise the Prizm or the TI-84+SE is for you. Maybe if you whine to TI, though, you might be able to get them to support Asm on the Nspire.