I think it depends a lot on what you are trying to do.
Here are some of my favorites
Steermakers: Purple Womaizer, bailout, KJ Manhattan
Cowmakers: P606, L18 or anything with 29F
Heifer bulls: Durango, tonic, Reedem
Show Heifers: Milsap, Tundra, Nitro, Bright future
I personally like the...