Write the 28th Amendment

[Deus Naturae]

Most of the amendments that come to mind would just prohibit government actions that are already prohibited under the current constitution, but are done regardless. Therefore, I can only conclude that any attempt to constitutionally limit the power of the federal government is pointless in the long term, and thus the only amendment that would actually change anything would be one to dissolve the federal constitution and abolish the federal government.

[Deus Naturae]

Here's one I particularly like: http://www.libertyamendment.com/.