[quote name='BattleChicken']
At that critical mass, it would be damn near impossible to beat that many regardless of what you made.. with the possible exception of other void rays...[/QUOTE]
I've only been playing custom games since the void patch, but as Zerg, a similar mass army of infestors and hydras should do the trick, now that they flat out out-range them.
As terran and protoss though, thats gonna be a thinker.
Edit: Never mind, wiki just told me that even after upgrades, Hydralisk have the same range of 6. Is that correct? Pre-patch i use to use cliffs to my advantage to single out hydralisks 1 by 1, but i was never able to hit them where they couldn't hit me. I assumed their range was the same.