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
Texas Instruments TI-86 Plus Graphing Calculator
TI-86 Graphing Calculator Black Texas Instruments TI 86 | eBay
Texas Instruments TI 84 Plus CE Color Graphing Calculator Rose Gold - Office Depot