These are the forums I'd look to merge and delete. First pass.
Please note, I only took a very quick pass at this.
TheSwamp FAQ (modify)
First things First
Code Red (modify)
AutoLISP (Vanilla / Visual)
Visual DCL Programming
* OpenDCL
* ObjectDCL
VB(A)
.NET
ARX Programming
General Programming (was C++)
* Dynamo
Show your stuff
CAD Forums (modify)
CAD General
* The Third Dimension
CAD Standards
* New to CAD
Dynamic Blocks
Revit
Plotting
* Vertically Challenged
* Architecturally Speaking
* Land Lubber / Geographically Positioned
* AutoCAD MEP
Speak and be Heard (modify)
News
* The Suggestion Box
Knowledge Base (modify)
Teach Me
* WebDev
Pixel This!
* Office Software
* Tips-n-Tricks
* Bits and Pcs
Other stuff (modify)
Lagniappe
Engineering Discussions/Questions
Block Lib
Sponsors Advertisers and Donors
Member Advertisements
Businesses
People ( by member name )
Job Junk
The Vent
Styles
Prince of Darkness