So here my answer/list to start ... I find that aggregator deal sites that are either completely or mostly tech focused are best. If a good deal pops up Amazon.com, Geeks.com, etc., they'll quickly appear on the aggregators, too, but there are some exceptions where to wait is to possibly miss out (woot!).
I regularly search these for myself & my clients (or just a bit of procrastination). I save them in a firefox folder and use "Open All in Tabs" almost daily.
dealcritic.com - people vote up the best deals, so you immediately get a sense of how much of a value it is
bensbargains.net - has trackers for certain hot products, quick, simple search
fatwallet.com - good for finding coupon codes and discussion on various deals if you're unsure of the product or merchant
dealnews.com - wide range of deals and coupon codes
dealnews.com/memory (aka dealram) - quickly find the best prices on the exact ram you need
pricewatch.com - great categorization, numerous merchants, great for searching when you need a certain type of product but you don't need a particular brand or model
froogle.com - quickly find an exact product (brand & model), but i prefer pricewatch for product types