I like both. It depends on what I'm promoting. Squidoo has modules and features I can use to promote certain types of products. Their iTunes model makes it easy to promote music.
Hubpages is well set up for exposure. Every new hub that's created gets initial visibility from the Hubpages feed on the homepage. Plus, forums are active. Questions get answered.
The interactivity in Hubpages is more prevalent. So it's a great way to get some initial traffic while you're working on ranking.
If you can find a way to optimize the use of both Hubpages and Squidoo together, you might find a winning formula that works.