Ion - Just feels right for putts. I've flirted with other molds over the years, but always go back to putting Ions.
Axis - Been my favorite mid since they came out. Nice glide and super straight. Excellent high speed stability combined with minimal low speed fadr makes it a great point and shoot disc. Holds release angles well. My beat Axis is an amazing disc too, flies some sexy turnover lines.
Volt - While the Crave and Wrath have stolen shots from my Volts, its still the driver I know the best. My go to is a seasoned eclipse Volt that's lost some low speed fade without gaining any high speed turn. It's the straightest speed 9 disc I've ever thrown. The day the Proton Volts came out is the day the hunt for a longer teebird ended for me.
I have some other molds I'm incredibly fond of, like the Envy, Proxy, Crave, Resistor, Wrath and Insanity, but those three discs are the backbone of my bag, and I could shoot well at any course with those three molds.