I'm pleased to report that the Encyclopedia Britannica 2004 Ultimate Reference Suite DVD does not suck, and in fact mostly rocks. The DVD includes both Mac and PC versions of decent software and a decent interface, my only complaint with which is the use of a proprietary windowing system that requires all articles to appear in little windows inside one big window. (No doubt they did this to make it cheaper to maintain both PC and Mac versions.) The software is stable, and while it's a tad sluggish, it never gets in my way. My biggest speed complaint is that it takes a while to start up the first time, which is a disadvantage for quick lookups. You can install the entire contents onto your hard drive for access without the disc inserted, or do a minimal install to save on hard drive space. It includes the full encyclopedias, Merriam-Webster's Collegiate Dictionary and Thesaurus, a world atlas, a few nifty browsing modes, and multimedia supplements to some articles. The best part is the price: $32.99 after $20 mail-in rebate.
The biggest complaint from Amazon.com reviewers is probably my biggest overall complaint: Many of the articles are out of date. What's worse is that some articles are more out of date than others, which means you cannot trust the timeliness of any of the information provided. (It'd be great of each article had a "last updated" date, but they don't.) Still, I would want to find corroborative sources for articles about events in the last 20 years anyway, and for most general subjects (like country profiles) it's obvious where their data ends. (Middle Eastern countries appear to have data up to 1992, for instance.)
I'm also pleased to recommend the CD-ROM that comes with Merriam-Webster's Collegiate Dictionary (also comes with the leather-bound edition). It too includes both PC and Mac versions, and installs completely to your hard drive. The best part: it's fast, popping through the complete alphabetical word list as you type, letting you hit return at any time to instantly display the definition. On my Mac, the software starts up in under 4 seconds. Despite the fact that MW comes with the Britannica suite, I'm definitely going to be using this version for all of my dictionary look-ups.