Not the most retro calculator out there, but the TI-86 is my favorite TI graphing calculator. I've still got all my games and stuff from high school (20+ years ago!) and I
Amazon.com: co2CREA Hard Case Compatible with Texas Instruments TI-84 Plus CE/TI-84 Plus/TI-Nspire CX II CAS/TI-Nspire CX II/TI-83 Plus/TI-89 Titanium/ TI-85 / TI-86 Color Graphing Calculator, Mint : Electronics
Texas Instruments Ti-86 Graphing Calculator With Cover - electronics - by owner - sale - craigslist