Add crushed Heath bars to the mocha [and leave out the Kahlúa] for a reasonable approximation of Ben & Jerry’s Coffee Toffee Crunch.
Substitute cocoa powder for the instant coffee (and leave out the Kahlúa) for basic chocolate. Add caramel sundae topping and bits of caramel pecan clusters [to basic chocolate] for turtle ice cream.
I’ve also been experimenting with daiquiri ice creams. Start with basic vanilla, add fruit and some rum extract or a tablespoon of real rum. This is where things get interesting: for raspberry, I add a pack of raspberry Jell-o powder. For blueberry, some blueberry pancake syrup.