As to the OP's question - - - - my favorite handgun chamberings are the 45 Colt and 44 Special. Big bullets that get the job done with little muzzle blast and little fuss. Either one is great.
I prefer the 4 5/8" barrel length; it just feels 'right' to me. But, I wouldnt turn down a 5 1/2" gun either - especially if the price was right. I prefer packin' revolvers with barrel lengths from 4" to 5 1/2" in length for the most part.