Don't you hate getting tank/lurker/dt/reaver dropped? Dont you wish you could stop it without looking like a newbie and making lots of cannons? Besides couldn't, corsiars/guradians/yamato could kill them?

If you answered yes to any of these three, then my plan might seem good. Dark archons. Now i dont mean gettiing huge squadrons of them, but just 4 or 5. Get mind control, energy upgrade, and maybe maelstorm (for against zerg) keep some observers around to see when they are going to drop and where. When you see them come close, you bring your Dark Archons in and mind control the dropshipe/shuttles/lurks. The best part about this is if they're protoss and u dont have a lot of teching, u get their ail/ground upgrades (shutles and ground attacking units in themm). And!! you can send them right back at em!! This is your choice. or you can supplement your choke defense with some tanks/lurks/free protoss units.

CreepColony's Opinion: This requires some micromanagement, and won't really work unless you see the drop ahead of time.