There are some really good quality sites hosting drama scripts which can be used for worship. Have a look at the main ones by following the links below.

The RUN network also has a large set of drama scripts but they're for members only. You can have a look at what RUN offers here

dramatrix.org - loads of Christian drama scripts. Most are free to use although a few have a small royalty fee.

fools4christ - loads more scripts, all free. This site also has a good directory pointing to other web sites hosting drama scripts for worship and events.