I use 155 gr. Gold Dots.  I know they are capable of delivering just about 500 ft/lbs of energy which would be on the lower end of a .357 mag if I'm not mistaken.  I know that energy isn't the only factor in determining how effective a round is, penetration as well as the hole it can make also matter.  That seems pretty impressive to me but to tell you the truth I'm not an expert and would like to find out if there is something better.  By the way I use them in a Glock 27.

There is no best round, just as there is no best caliber or best gun.  "Best" is defined by situation---what is the best in Situation A might be the worst in Situation B.  All the modern designer rounds, like your Gold Dots, are designed to provide performance in a particualr envelope.  Each round will have its own little differences, but which difference will be important at a particular time is somethign that is hard to predict.  Buy whatever designer round is on sale and you'll have made as good selection as anybody else.