Semen Quality

I have read several posts that mentioned semen quality on various bulls.  Just to throw this out there, what bull have you all had the best luck with in terms of semen quality?  Especially in terms of the Heat Wave sons.  I have had tremendous conception rates with Invincible and Leroy Brown.  Non Heat Wave sons, I have had the best luck with Kadabra and Full Flush (after the clones came out).