I've been a long time fan of fatwallet. It is a great way to keep up on deals and random finance related talk. Although the finance side has turned more into an App-O-Rama board than anything, which is something I have little interest in. The interest rate arbitrage is interesting, and maybe if I had more time and more trust in the credit card companies and credit rating companies, I would do one myself.
Another site that I haven't used much, but was recently listed in PC-Mag is Dealio. This is a price finder website/aggregator. Seems to work alright, but there are plenty out there already; PriceGrabber, PriceWatch, etc...
Slickdeals is another site much like fatwallet. However, it seems to get better traffic on the deal side than fatwallet. If I am ever shopping for something significant (a computer or something), I keep an eye on both slickdeals and fatwallet for a while before pulling the trigger. I just recently saw in PC-mag that slickdeals has a fillers function on their website. It helps you find the least expensive item(s) necessary to make the 25$ free shipping at Amazon possible.