PostGIS In Action Desktop Tools that Support PostGIS

We are working on second edition of PostGIS in Action 2ed for availability sometime in late 2013/early 2014. Early purchase review (MEAP) is now available for Second Edition. With MEAP you can get chapter updates as we write them and get the final polished copy at release time.

Our most recent book PostgreSQL: Up and Running is out in both E-book and hard-copy. You can order hard-copy now from Amazon or Kindle or hard-copy or e-Book from O'Reilly .

PostGIS in Action: Desktop Tools that Support PostGIS

Tools with * are covered in the book

Open Source Desktop Tools

OpenJump*
QuantumGIS*
uDig*
GvSig*
GearScape
OrbisGIS
ZigGIS PostGIS connector is an ArcGIS plugin that allows querying PostGIS data without the need of ArcSDE. It goes without saying, that you need an ArcGIS license to use it. The 2.0 series was under a commercial open source license. The upcoming 3 series is under a regular FOSS license.
PgAdmin III plugin PostGISViewer plugin for Microsoft Windows. Useful for rendering ad-hoc queries directly from pgAdmin III and built using MapWindow.NET SDK. We have an article describing how to install the PostGIS Viewer

Proprietary Desktop Tools

CadCorp SIS
Manifold.net
MapInfo Professional 10+
AutoCAD and AutoDesk family of tools. Note the FDO PostGIS driver is beta quality as of this writing and according to comments there is a planned rewrite of it by AutoDesk. This article discusses getting up and going with AutoCad and PostGIS
ESRI ArcGIS desktop via ArcSDE license. Take a look at ZigGIS if you don't want to shell out the money for ArcSDE and just need to use in ArcMap or other ArcGIS desktop tool.