Plugin Name: GriefPrevention
BukkitDev Link: http://dev.bukkit.org/server-mods/grief-prevention/
Description: Very easy to use self serve region protection! Has support for subdivisions, container trust, full trust, or just door/button access trust! Stops lava, fire spread, ability to disable use of water/lava outside claims, and stops explosion damage above sea level; even stops most tekkit explosions (nukes, reactors, engines) with exception to nova cataclysm and catalyst. The plugin can use either flatfile or database for data storage (blocks earned, claims). Pretty much everything in the plugin can be toggled on or off if you don't want a certain function. Also has support for dynmap to show claims, claim owner, and the people that are trusted into claim. Theres a few more features that i forgot to mention, but most importantly the author of the plugin seems to listen to the tekkit crowd as the modded item list was a product of that!
Tekkit Compatibility: Very compatible with tekkit as of recent patches. You must use version 5.5.1! Previous versions had a buggy mod item list, that would wipe itself but only wipe the mod items, nothing else in config. It protects claims from everything except the nova catalyst/cataclysm, and computer craft turtles. I can't say much for the EE red matter or dark matter tools as I don't have those enabled in my server.
I highly recommend this as a set it and forget it region protection plugin! Ive been using it since 2.1.1, and it still impresses me as I use it more. Its definitely worth watching a few of the videos the author made on it.