Best cartridge for Rega RB- 250?

Looking to upgrade from Grado red .
I used for a long time a Grado Reference Platinum MM and Nagaoka MP-11.

The MP-11 is hard to beat for the price.
Nice system, McPhile. I bet those Klipsch's sound wonderful driven by your McIntosh gear. I agree with Johnnyb53......the Rega Exact should work well.
Personally, I'm extremely happy with my Rega P3-24/Rega RB-301/Rega Exact 2 combination. Good Luck, and Happy Listening.