Does anyone have any? I've been using Invision but with each new revision it gets buggier and buggier,
That happens quite alot. Even from a script writer's point of view, myself included, nothing beats a script coded from scratch, perhaps with one revision to sort out bugs due to typographical errors.
What Poppy said about the possibility of scripts being bad is true to a point. Some scripts are good and have the following and reputation they deserve. Others are nasty, some even being quite dangerous from a data integrity and security aspect. It's a case of Caveat Emptor (Let the buyer [downloader] beware).
The best script is the script one makes for themselves. For those that like using scripts made by others, choose carefully, download one that doesn't have bugs, better still download something that suits the networks you connect to. Most importantly though, and this advice is ignored by millions of IRC users - if you do use something made by someone else, scan it for trojans and other bad files before using it. And if in the slightest doubt, delete it and get something else.