hmm- not bad ideas everyone. but you have to take into consideration other things. as the game progresses your once unsurmountable army will be nothing to the new combo created by your enemy. like jiggy said. Goons and zealots would be a awesome combo. for the first ten minutes. siege tanks rip the goons, wriaths can pick apart zealots. Mutas slice up the zealots. defiler and zergling will own any long ranged ground army. so basicley here is my idea for PROTOSS.
beggining - goons and zealots - middle - pull goons and zealots back to help defend base (always remember 2 upgrade!) take out corsairs to deal with scourges. and scouts along with dark templar and archons. also dark archons would be helpful high templar also - nearing end of the game - Arbiters along with carriars and carriars are gaurded by corsairs and scouts. along with the ground come dark templars and archons with high templar for hallucination and storms-dark archons for maelstrom and feedback if u can mind control.
ZERG!
START - zerglings hydras upgrade both! - MIDDLE - lings and lurkers along with muta's (get devs scourge and gaurds if u can) - NEARING END - Upgrade lots - lots of scourges 2 take out air, devs 2 back up scourge, gaurds 2 protect devs from ground, lots of lurkers and defiler and lings (maybe ultras)
TERRAN!
START- bats and rines and meds with stim - MIDDLE - gols and siege tanks with seige mode upgrade gol missle range valks and wraiths also with cloak!- NEARING END - Gols and siege tanks - Valks, wraiths cloaked, and bc's.